Memory For A G4 Mac

• Memory For A G4 Macbook
• Memory For A G4 Mac Pro

Explore the world of Mac. Check out MacBook Pro, iMac Pro, MacBook Air, iMac, and more. Visit the Apple site to learn, buy, and get support.

Upgrade the memory of nearly any iMac, MacBook Pro, Mac Pro, or Mac mini. Save money by trading in your original memory chips for a cash rebate. Compatible Apple Memory upgrades for Apple Power Macintosh G4, all Apple Memory upgrades listed carries a lifetime warranty and is tested for quality. Samsung RAM Memory for Apple Mac, Apple iMac, Apple iBook, Apple PowerBook Memory RAM Upgrade. Mac Mini Memory for Model 1.1: Mac Mini Early 2006 and Late 2006 DDR2-667Mhz. The original Mac Mini Intel has two memory slots. It is preloaded from the factory with two 256mb DDR2-667 SO-DIMMs. Mac Mini Memory for Model PowerMac10.1 and PowerMac 10.2: 2005 PowerPC G4 DDR400. The Mac Mini or PowerMac G4 has one memory slot, which.

Memory For A G4 Macbook

Choose your iMac model

If you're not sure which iMac you have, you can identify your iMac and then select it from the list below.

27-inch

24-inch

21.5-inch

• iMac (Retina 4K, 21.5-inch, 2019)*
• iMac (Retina 4K, 21.5-inch, 2017)*
• iMac (21.5-inch, 2017)*
• iMac (21.5 inch, Mid 2014)*
• iMac (21.5-inch, Late 2013)*
• iMac (21.5-inch, Late 2012)*

20-inch

17-inch

* Memory is not removable by users on iMac (21.5-inch, Late 2012), iMac (21.5-inch, Late 2013), iMac (21.5-inch, Mid 2014), iMac (21.5-inch, 2017), iMac (Retina 4K, 21.5-inch, 2017), and iMac (Retina 4K, 21.5-inch, 2019). If the memory in one of these computers needs repair service, contact an Apple Retail Store or Apple Authorized Service Provider. If you'd like to upgrade the memory in one of these models, an Apple Authorized Service Provider can help. Before you schedule an appointment, confirm that the specific Apple Authorized Service Provider offers memory upgrade services.

Memory in iMac (21.5-inch, Late 2015), and iMac (Retina 4K, 21.5-inch, Late 2015) is not upgradeable.

iMac (Retina 5K, 27-inch, 2020)

Get memory specifications for iMac (Retina 5K, 27-inch, 2020), then learn how to install memory in this model.

Memory specifications

This iMac model features Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

For optimal memory performance, DIMMs should be the same capacity, speed, and vendor. Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

• PC4-21333
• Unbuffered
• Nonparity
• 260-pin
• 2666MHz DDR4 SDRAM

If you have mixed capacity DIMMs, see the install memory section for installation recommendations.

iMac (Retina 5K, 27-inch, 2019)

Get memory specifications for iMac (Retina 5K, 27-inch, 2019), then learn how to install memory in this model.

Memory specifications

This iMac model features Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

• PC4-21333
• Unbuffered
• Nonparity
• 260-pin
• 2666MHz DDR4 SDRAM

iMac (Retina 5K, 27-inch, 2017)

Get memory specifications for iMac (Retina 5K, 27-inch, 2017), then learn how to install memory in this model.

Memory specifications

This iMac model features Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

• PC4-2400 (19200)
• Unbuffered
• Nonparity
• 260-pin
• 2400MHz DDR4 SDRAM

iMac (Retina 5K, 27-inch, Late 2015)

Get memory specifications for iMac (Retina 5K, 27-inch, Late 2015), then learn how to install memory in this model.

Memory specifications

This iMac model features Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

• PC3-14900
• Unbuffered
• Nonparity
• 204-pin
• 1867MHz DDR3 SDRAM

For these 27-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

• iMac (Retina 5K, 27-inch, Mid 2015)
• iMac (Retina 5K, 27-inch, Late 2014)
• iMac (27-inch, Late 2013)
• iMac (27-inch, Late 2012)

Memory specifications

These iMac models feature Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

• PC3-12800
• Unbuffered
• Nonparity
• 204-pin
• 1600MHz DDR3 SDRAM

Installing memory

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After you shut down your iMac and give it time to cool, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Open the memory compartment door by pressing the small grey button located just above the AC power port:
5. The memory compartment door will open as the button is pushed in. Remove the compartment door and set it aside:
6. A diagram on the underside of the compartment door shows the memory cage levers and the orientation of the DIMM. Locate the two levers on the right and left sides of the memory cage. Push the two levers outward to release the memory cage:
7. After the memory cage is released, pull the memory cage levers toward you, allowing access to each DIMM slot.
8. Remove a DIMM by pulling the module straight up and out. Note the location of the notch on the bottom of the DIMM. When reinstalling DIMMs, the notch must be oriented correctly or the DIMM won't fully insert:
9. Replace or install a DIMM by setting it down into the slot and pressing firmly until you feel the DIMM click into the slot. When you insert a DIMM, make sure to align the notch on the DIMM to the DIMM slot. Find your model below for specific installation instructions and notch locations:
   • iMac (Retina 5K, 27-inch, 2020) DIMMs have a notch on the bottom, slightly left of the middle. If your DIMMs are mixed in capacity, minimize the capacity difference between Channel A (slots 1 and 2) and Channel B (slots 3 and 4) when possible.
     
   • iMac (Retina 5K, 27-inch, 2019) DIMMs have a notch on the bottom, slightly left of the middle:
   • iMac (27-inch, Late 2012) and iMac (Retina 5K, 27-inch, 2017) DIMMs have a notch on the bottom left:
     
   • iMac (27-inch, Late 2013) and iMac (Retina 5K, 27-inch, Late 2014, Mid 2015, and Late 2015) DIMMs have a notch on the bottom right:
     
10. After you install all of your DIMMs, push both memory cage levers back into the housing until they lock into place:
    
11. Replace the memory compartment door. You don't need to press the compartment door release button when replacing the compartment door.
12. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.
    

Your iMac performs a memory initialization procedure when you first turn it on after upgrading memory or rearranging DIMMs. This process can take 30 seconds or more, and the display of your iMac remains dark until it's finished. Make sure to let the memory initialization complete.

For these 27-inch and 21.5-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

• iMac (27-inch, Mid 2011)
• iMac (21.5-inch, Mid 2011)
• iMac (27-inch, Mid 2010)
• iMac (21.5-inch, Mid 2010)
• iMac (27-inch, Late 2009)
• iMac (21.5-inch, Late 2009)

Memory specifications

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

i5 and i7 Quad Core iMac computers come with both top memory slots populated. These computers will not start up if only a single DIMM is installed in any bottom slot; these computers should operate normally with a single DIMM installed in any top slot.

Core Duo iMac computers should operate normally with a single DIMM installed in any slot, top or bottom. ('Top' and 'bottom' slots refer to the orientation of the slots in the pictures below. 'Top' refers to the slots closest to the display; 'bottom' refers to the slots closest to the stand.)

Installing memory

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After you shut down your iMac and give it time to cool, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Using a Philips screwdriver, remove the RAM access door in the bottom of your computer:
   
5. Remove the access door and set it aside.
6. Untuck the tab in the memory compartment. If you're replacing a memory module, gently pull the tab to eject any installed memory module:
   
7. Insert your new or replacement SO-DIMM into the empty slot, noting the orientation of the keyway of the SO-DIMM as shown below.
8. After you insert it, press the DIMM up into the slot. There should be a slight click when you seat the memory correctly:
   
9. Tuck the tabs above the memory DIMMs, and reinstall the memory access door:
   
10. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

For these 24-inch and 20-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

• iMac (24-inch, Early 2009)
• iMac (20-inch, Early 2009)
• iMac (24-inch, Early 2008)
• iMac (20-inch, Early 2008)
• iMac (24-inch Mid 2007)
• iMac (20-inch, Mid 2007)

Memory specifications

These iMac computers have two side-by-side Synchronous Dynamic Random-Access Memory (SDRAM) slots in the bottom of the computer.

The maximum amount of random-access memory (RAM) you can install in each computer is:

You can use a 1GB or 2GB RAM module in each slot for iMac (Mid 2007) and iMac (Early 2008). Use 1GB, 2GB, or 4GB modules in each slot for the iMac (Early 2009).

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

DIMMs with any of the following features aren't supported:

• Registers or buffers
• PLLs
• Error-correcting code (ECC)
• Parity
• Extended data out (EDO) RAM

Installing memory

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After your iMac cools down, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Using a Philips screwdriver, remove the RAM access door in the bottom of the computer:
   
5. Remove the access door and set it aside.
6. Untuck the tab in the memory compartment. If you're replacing a memory module, untuck the tab and pull it to eject any installed memory module:
   
7. Insert your new or replacement RAM SO-DIMM into the empty slot, noting the orientation of the keyway of the SO-DIMM as shown above.
8. After you insert it, press the DIMM up into the slot. There should be a slight click when you seat the memory correctly.
9. Tuck the tabs above the memory DIMMs, and reinstall the memory access door:
   
10. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

For these 20-inch and 17-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

• iMac (20-inch Late 2006)
• iMac (17-inch, Late 2006 CD)
• iMac (17-inch, Late 2006)
• iMac (17-inch, Mid 2006)
• iMac (20-inch, Early 2006)
• iMac (17-inch, Early 2006)

Memory specifications

Mac os x mountain lion vmware image for amd desktop. For best performance, fill both memory slots, installing an equal memory module in each slot.
*iMac (Late 2006) uses a maximum of 3 GB of RAM.

Installing memory in the bottom slot

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After you shut down your iMac and give it time to cool, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Using a Phillips screwdriver, remove the RAM access door on the bottom of the iMac and set it aside:
   
5. Move the DIMM ejector clips to their fully open position:
   
6. Insert your RAM SO-DIMM into the bottom slot, keeping in mind the orientation of the keyed SO-DIMM:
   
7. After you insert it, press the DIMM up into the slot with your thumbs. Don't use the DIMM ejector clips to push in the DIMM, as this might damage the SDRAM DIMM. There should be a slight click when you seat the memory fully.
8. Close the ejector clips:
   
9. Reinstall the memory access door:
   
10. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

Replacing memory in the top slot

After you shut down your iMac and give it time to cool, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Using a Phillips screwdriver, remove the RAM access door on the bottom of the iMac and set it aside:
   
5. Pull the two levers on each side of the memory compartment to eject the memory module that's already installed:
   
6. Remove the memory module from your iMac as shown below:
   
7. Insert your RAM SO-DIMM into the top slot, noting the orientation of the keyed SO-DIMM:
   
8. After you insert it, press the DIMM up into the slot with your thumbs. Don't use the DIMM ejector clips to push in the DIMM, as this might damage the SDRAM DIMM. There should be a slight click when you seat the memory fully.
9. Close the ejector clips:
   
10. Reinstall the memory access door:
    
11. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

If your iMac makes a tone after you install memory

iMac models introduced before 2017 might make a warning sound when you start up after installing or replacing memory:

• One tone, repeating every five seconds signals that no RAM is installed.
• Three successive tones, then a five-second pause (repeating) signals that RAM doesn't pass a data integrity check.

If you hear these tones, confirm that the memory you installed is compatible with your iMac and that it's installed correctly by reseating the memory. If your Mac continues to make the tone, contact Apple Support.

Confirm that your iMac recognizes its new memory

After you install memory, you should confirm that your iMac recognizes the new RAM by choosing Apple () menu > About This Mac.

The window that appears lists the total memory, including the amount of memory that originally came with the computer plus the newly added memory. If all the memory in the iMac has been replaced, it lists the new total of all installed RAM.

For detailed information about the memory installed in your iMac, click System Report. Then choose Memory under the Hardware section in the left side of System Information.

If your computer doesn't recognize the memory or doesn't start up correctly, confirm that the RAM you installed is compatible with your iMac and that it's installed correctly by reseating the memory. If you continue to have issues with the memory in your iMac, contact Apple Support.

The Power Mac G4 is a series of personal computers designed, manufactured, and sold by Apple Computer, Inc. from 1999 to 2004 as part of the Power Macintosh line. Built around the PowerPC G4 series of microprocessors, the Power Mac G4 was marketed by Apple as the first 'personal supercomputers',^[1] reaching speeds of 4 to 20 gigaFLOPS. This was the first existing Macintosh product to be officially shortened as 'Mac', and is the last Mac able to boot into classic Mac OS.

The enclosure style introduced with the Power Macintosh G3 (Blue and White) was retained through its entire five year production run of the Power Mac G4, albeit with significant changes to match Apple's evolving industrial design and to accommodate increasing cooling needs. The G4 and the enclosure were retired with the introduction of the Power Mac G5.

PCI Graphics/AGP Graphics/Gigabit Ethernet[edit]

The original Power Mac G4 was introduced at the Seybold conference in San Francisco on August 31, 1999.^[2] There were two variants, officially titled Power Mac G4 (AGP Graphics) with 400 MHz, 450 MHz and 500 MHz configurations available, and Power Mac G4 (PCI Graphics), with 350 MHz and 400 MHz configurations. Colloquially, this generation of Power Mac is referred to as 'Graphite', owing to the colors of the case being similar to the iMac G3 Graphite.

Apple originally planned to ship the 500 MHz configuration in October 1999, but they were forced to postpone this because of poor yield of the CPUs. In response, Apple reduced the clock speed of the processor in each configuration by 50 MHz (making the options 350 MHz, 400 MHz and 450 MHz), which caused some controversy because they did not lower the original prices.^[3]

The early 400 MHz (later 350 MHz) PCI-based version used a motherboard identical to the one used in Power Macintosh G3 (Blue and White) computers including the use of Zero Insertion Force (ZIF) processors sockets^[4] (minus the ADB port), in a 'graphite' colored case and with the new MotorolaPowerPC 7400 (G4) CPU. The higher-speed models, code name 'Sawtooth', used a greatly modified motherboard design with AGP 2x graphics (replacing the 66 MHz PCI slot).

The PCI variant was discontinued at the end of 1999.^[5]

The machines featured DVD-ROM drives as standard. The 400 MHz and 450 MHz versions had 100 MBZip drives as standard equipment, and as an option on the 350 MHz Sawtooth. This series had a 100 MHzsystem bus and four PC100SDRAM slots for up to 2 GB of RAM (1.5 GB under Mac OS 9). The AGP Power Macs were the first to include an AirPort slot and DVI video port. The computers could house a total of three hard drives, two 128 GB ATA hard drives and up to a single 20GB SCSI hard drive, with the installation of a SCSI card.

Memory For A G4 Mac Pro

The 500 MHz version was reintroduced on February 16, 2000, accompanied by 400 MHz and 450 MHz models. DVD-RAM and Zip drives featured on these later 450 MHz and 500 MHz versions and were an option on the 400 MHz.

The Power Mac G4 (Gigabit Ethernet) model was introduced at Macworld ExpoNew York on July 19, 2000; the new revision included dual-processor 450 MHz and 500 MHz versions, and a low-end single CPU 400 MHz model. It was also the first personal computer to include gigabit Ethernet as standard. Most people saw this revision as a stopgap release, because higher clocked G4s were not available; the G4's Motorola XPC107 'Grackle' PCI/Memory controller prevented the G4 from hitting speeds higher than 500 MHz.^{[citation needed]} The dual 500 MHz models featured DVD-RAM optical drive. Zip drives were optional on all models. These models also introduced Apple's proprietary Apple Display Connector video port.

Digital Audio/Quicksilver[edit]

A new line with a revamped motherboard but the familiar 'Graphite' case debuted on January 9, 2001. Known officially as the Power Mac G4 (Digital Audio), it is in effect a Quicksilver design inside the Graphite enclosure. Motorola had added a seventh pipeline stage in the new PowerPC G4 design to achieve faster clock frequencies. New features included a fourth PCI slot, a 133 MHz system bus, an improved 4X AGP slot, and a new 'digital audio' Tripath Class T amplifier sound system. The models were offered in 466 MHz, 533 MHz, dual 533 MHz, 667 MHz and 733 MHz configurations, the latter two using a newer PowerPC 7450 processor. The number of RAM slots was reduced to three, accommodating up to 1.5 Gigabytes of PC133SDRAM.

The 733 MHz model was the first Macintosh to include a built-in DVD-R or Apple-branded SuperDrive, the rest of the line became the first Macs to ship with CD-RW drives. This was also the first series of Macs to include an Nvidia graphics card, the GeForce 2MX.

At Macworld ExpoNew York on July 18, 2001, a new line debuted featuring a cosmetically redesigned case known as Quicksilver, and various upgrades to the specifications. It was available in 733 MHz, 867 MHz and dual 800 MHz configurations. The 733 MHz model was notable for not having a level three cache. The SuperDrive was offered on the mid-range 867 MHz model, and UltraATA/100 hard drives were offered on all models. The internal speaker received an upgrade, using a Harman/Kardon speaker.

Quicksilver received criticism in MacWorld's review for removing the 'eject' button and the manual eject pinhole, as well as the pass-through monitor power plug, and for the base specification of 128 MB RAM as being insufficient for running Mac OS X.^[6]

Updated Quicksilver machines, officially named Power Mac G4 (QuickSilver 2002), were introduced on January 28, 2002 with 800 MHz, 933 MHz and dual 1 GHz configurations. This was the first Mac to reach 1 GHz. Again, the low end 800 MHz model did not include any level three cache. The graphics in this series were provided by an Nvidia GeForce4 MX400 card. Some of these models have ATA controllers with 48 bit LBA for hard drives larger than 128 GB.

Mirrored Drive Doors/FW800[edit]

Another generation of Apple Power Mac G4s, officially named 'Mirrored Drive Doors' (MDD), was introduced on August 13, 2002, featuring both a new Xserve-derived DDR motherboard architecture and a new case design. All models were available in dual processor configurations running at 867 MHz, 1 GHz or 1.25 GHz. As with the Xserves, the PowerPC 7455 CPU used does not have a DDR frontside bus, meaning the CPU could only use at most 50% of the new system's theoretical memory bandwidth, providing no improvement over previous models. The rest was available to the graphics card and I/O systems. A single processor 1.25 GHz model would be the last Power Mac G4 the company offered to the public after the announcement of the new Power Mac G5, introduced in June 2003.

• PC3-12800
• Unbuffered
• Nonparity
• 204-pin
• 1600MHz DDR3 SDRAM

Installing memory

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After you shut down your iMac and give it time to cool, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Open the memory compartment door by pressing the small grey button located just above the AC power port:
5. The memory compartment door will open as the button is pushed in. Remove the compartment door and set it aside:
6. A diagram on the underside of the compartment door shows the memory cage levers and the orientation of the DIMM. Locate the two levers on the right and left sides of the memory cage. Push the two levers outward to release the memory cage:
7. After the memory cage is released, pull the memory cage levers toward you, allowing access to each DIMM slot.
8. Remove a DIMM by pulling the module straight up and out. Note the location of the notch on the bottom of the DIMM. When reinstalling DIMMs, the notch must be oriented correctly or the DIMM won't fully insert:
9. Replace or install a DIMM by setting it down into the slot and pressing firmly until you feel the DIMM click into the slot. When you insert a DIMM, make sure to align the notch on the DIMM to the DIMM slot. Find your model below for specific installation instructions and notch locations:
   • iMac (Retina 5K, 27-inch, 2020) DIMMs have a notch on the bottom, slightly left of the middle. If your DIMMs are mixed in capacity, minimize the capacity difference between Channel A (slots 1 and 2) and Channel B (slots 3 and 4) when possible.
     
   • iMac (Retina 5K, 27-inch, 2019) DIMMs have a notch on the bottom, slightly left of the middle:
   • iMac (27-inch, Late 2012) and iMac (Retina 5K, 27-inch, 2017) DIMMs have a notch on the bottom left:
     
   • iMac (27-inch, Late 2013) and iMac (Retina 5K, 27-inch, Late 2014, Mid 2015, and Late 2015) DIMMs have a notch on the bottom right:
     
10. After you install all of your DIMMs, push both memory cage levers back into the housing until they lock into place:
    
11. Replace the memory compartment door. You don't need to press the compartment door release button when replacing the compartment door.
12. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.
    

Your iMac performs a memory initialization procedure when you first turn it on after upgrading memory or rearranging DIMMs. This process can take 30 seconds or more, and the display of your iMac remains dark until it's finished. Make sure to let the memory initialization complete.

For these 27-inch and 21.5-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

• iMac (27-inch, Mid 2011)
• iMac (21.5-inch, Mid 2011)
• iMac (27-inch, Mid 2010)
• iMac (21.5-inch, Mid 2010)
• iMac (27-inch, Late 2009)
• iMac (21.5-inch, Late 2009)

Memory specifications

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

i5 and i7 Quad Core iMac computers come with both top memory slots populated. These computers will not start up if only a single DIMM is installed in any bottom slot; these computers should operate normally with a single DIMM installed in any top slot.

Core Duo iMac computers should operate normally with a single DIMM installed in any slot, top or bottom. ('Top' and 'bottom' slots refer to the orientation of the slots in the pictures below. 'Top' refers to the slots closest to the display; 'bottom' refers to the slots closest to the stand.)

Installing memory

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After you shut down your iMac and give it time to cool, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Using a Philips screwdriver, remove the RAM access door in the bottom of your computer:
   
5. Remove the access door and set it aside.
6. Untuck the tab in the memory compartment. If you're replacing a memory module, gently pull the tab to eject any installed memory module:
   
7. Insert your new or replacement SO-DIMM into the empty slot, noting the orientation of the keyway of the SO-DIMM as shown below.
8. After you insert it, press the DIMM up into the slot. There should be a slight click when you seat the memory correctly:
   
9. Tuck the tabs above the memory DIMMs, and reinstall the memory access door:
   
10. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

For these 24-inch and 20-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

• iMac (24-inch, Early 2009)
• iMac (20-inch, Early 2009)
• iMac (24-inch, Early 2008)
• iMac (20-inch, Early 2008)
• iMac (24-inch Mid 2007)
• iMac (20-inch, Mid 2007)

Memory specifications

These iMac computers have two side-by-side Synchronous Dynamic Random-Access Memory (SDRAM) slots in the bottom of the computer.

The maximum amount of random-access memory (RAM) you can install in each computer is:

You can use a 1GB or 2GB RAM module in each slot for iMac (Mid 2007) and iMac (Early 2008). Use 1GB, 2GB, or 4GB modules in each slot for the iMac (Early 2009).

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

DIMMs with any of the following features aren't supported:

• Registers or buffers
• PLLs
• Error-correcting code (ECC)
• Parity
• Extended data out (EDO) RAM

Installing memory

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After your iMac cools down, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Using a Philips screwdriver, remove the RAM access door in the bottom of the computer:
   
5. Remove the access door and set it aside.
6. Untuck the tab in the memory compartment. If you're replacing a memory module, untuck the tab and pull it to eject any installed memory module:
   
7. Insert your new or replacement RAM SO-DIMM into the empty slot, noting the orientation of the keyway of the SO-DIMM as shown above.
8. After you insert it, press the DIMM up into the slot. There should be a slight click when you seat the memory correctly.
9. Tuck the tabs above the memory DIMMs, and reinstall the memory access door:
   
10. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

For these 20-inch and 17-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

• iMac (20-inch Late 2006)
• iMac (17-inch, Late 2006 CD)
• iMac (17-inch, Late 2006)
• iMac (17-inch, Mid 2006)
• iMac (20-inch, Early 2006)
• iMac (17-inch, Early 2006)

Memory specifications

Mac os x mountain lion vmware image for amd desktop. For best performance, fill both memory slots, installing an equal memory module in each slot.
*iMac (Late 2006) uses a maximum of 3 GB of RAM.

Installing memory in the bottom slot

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After you shut down your iMac and give it time to cool, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Using a Phillips screwdriver, remove the RAM access door on the bottom of the iMac and set it aside:
   
5. Move the DIMM ejector clips to their fully open position:
   
6. Insert your RAM SO-DIMM into the bottom slot, keeping in mind the orientation of the keyed SO-DIMM:
   
7. After you insert it, press the DIMM up into the slot with your thumbs. Don't use the DIMM ejector clips to push in the DIMM, as this might damage the SDRAM DIMM. There should be a slight click when you seat the memory fully.
8. Close the ejector clips:
   
9. Reinstall the memory access door:
   
10. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

Replacing memory in the top slot

After you shut down your iMac and give it time to cool, follow these steps:

1. Disconnect the power cord and all other cables from your computer.
2. Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
3. Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
4. Using a Phillips screwdriver, remove the RAM access door on the bottom of the iMac and set it aside:
   
5. Pull the two levers on each side of the memory compartment to eject the memory module that's already installed:
   
6. Remove the memory module from your iMac as shown below:
   
7. Insert your RAM SO-DIMM into the top slot, noting the orientation of the keyed SO-DIMM:
   
8. After you insert it, press the DIMM up into the slot with your thumbs. Don't use the DIMM ejector clips to push in the DIMM, as this might damage the SDRAM DIMM. There should be a slight click when you seat the memory fully.
9. Close the ejector clips:
   
10. Reinstall the memory access door:
    
11. Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

If your iMac makes a tone after you install memory

iMac models introduced before 2017 might make a warning sound when you start up after installing or replacing memory:

• One tone, repeating every five seconds signals that no RAM is installed.
• Three successive tones, then a five-second pause (repeating) signals that RAM doesn't pass a data integrity check.

If you hear these tones, confirm that the memory you installed is compatible with your iMac and that it's installed correctly by reseating the memory. If your Mac continues to make the tone, contact Apple Support.

Confirm that your iMac recognizes its new memory

After you install memory, you should confirm that your iMac recognizes the new RAM by choosing Apple () menu > About This Mac.

The window that appears lists the total memory, including the amount of memory that originally came with the computer plus the newly added memory. If all the memory in the iMac has been replaced, it lists the new total of all installed RAM.

For detailed information about the memory installed in your iMac, click System Report. Then choose Memory under the Hardware section in the left side of System Information.

If your computer doesn't recognize the memory or doesn't start up correctly, confirm that the RAM you installed is compatible with your iMac and that it's installed correctly by reseating the memory. If you continue to have issues with the memory in your iMac, contact Apple Support.

The Power Mac G4 is a series of personal computers designed, manufactured, and sold by Apple Computer, Inc. from 1999 to 2004 as part of the Power Macintosh line. Built around the PowerPC G4 series of microprocessors, the Power Mac G4 was marketed by Apple as the first 'personal supercomputers',^[1] reaching speeds of 4 to 20 gigaFLOPS. This was the first existing Macintosh product to be officially shortened as 'Mac', and is the last Mac able to boot into classic Mac OS.

The enclosure style introduced with the Power Macintosh G3 (Blue and White) was retained through its entire five year production run of the Power Mac G4, albeit with significant changes to match Apple's evolving industrial design and to accommodate increasing cooling needs. The G4 and the enclosure were retired with the introduction of the Power Mac G5.

PCI Graphics/AGP Graphics/Gigabit Ethernet[edit]

The original Power Mac G4 was introduced at the Seybold conference in San Francisco on August 31, 1999.^[2] There were two variants, officially titled Power Mac G4 (AGP Graphics) with 400 MHz, 450 MHz and 500 MHz configurations available, and Power Mac G4 (PCI Graphics), with 350 MHz and 400 MHz configurations. Colloquially, this generation of Power Mac is referred to as 'Graphite', owing to the colors of the case being similar to the iMac G3 Graphite.

Apple originally planned to ship the 500 MHz configuration in October 1999, but they were forced to postpone this because of poor yield of the CPUs. In response, Apple reduced the clock speed of the processor in each configuration by 50 MHz (making the options 350 MHz, 400 MHz and 450 MHz), which caused some controversy because they did not lower the original prices.^[3]

The early 400 MHz (later 350 MHz) PCI-based version used a motherboard identical to the one used in Power Macintosh G3 (Blue and White) computers including the use of Zero Insertion Force (ZIF) processors sockets^[4] (minus the ADB port), in a 'graphite' colored case and with the new MotorolaPowerPC 7400 (G4) CPU. The higher-speed models, code name 'Sawtooth', used a greatly modified motherboard design with AGP 2x graphics (replacing the 66 MHz PCI slot).

The PCI variant was discontinued at the end of 1999.^[5]

The machines featured DVD-ROM drives as standard. The 400 MHz and 450 MHz versions had 100 MBZip drives as standard equipment, and as an option on the 350 MHz Sawtooth. This series had a 100 MHzsystem bus and four PC100SDRAM slots for up to 2 GB of RAM (1.5 GB under Mac OS 9). The AGP Power Macs were the first to include an AirPort slot and DVI video port. The computers could house a total of three hard drives, two 128 GB ATA hard drives and up to a single 20GB SCSI hard drive, with the installation of a SCSI card.

Memory For A G4 Mac Pro

The 500 MHz version was reintroduced on February 16, 2000, accompanied by 400 MHz and 450 MHz models. DVD-RAM and Zip drives featured on these later 450 MHz and 500 MHz versions and were an option on the 400 MHz.

The Power Mac G4 (Gigabit Ethernet) model was introduced at Macworld ExpoNew York on July 19, 2000; the new revision included dual-processor 450 MHz and 500 MHz versions, and a low-end single CPU 400 MHz model. It was also the first personal computer to include gigabit Ethernet as standard. Most people saw this revision as a stopgap release, because higher clocked G4s were not available; the G4's Motorola XPC107 'Grackle' PCI/Memory controller prevented the G4 from hitting speeds higher than 500 MHz.^{[citation needed]} The dual 500 MHz models featured DVD-RAM optical drive. Zip drives were optional on all models. These models also introduced Apple's proprietary Apple Display Connector video port.

Digital Audio/Quicksilver[edit]

A new line with a revamped motherboard but the familiar 'Graphite' case debuted on January 9, 2001. Known officially as the Power Mac G4 (Digital Audio), it is in effect a Quicksilver design inside the Graphite enclosure. Motorola had added a seventh pipeline stage in the new PowerPC G4 design to achieve faster clock frequencies. New features included a fourth PCI slot, a 133 MHz system bus, an improved 4X AGP slot, and a new 'digital audio' Tripath Class T amplifier sound system. The models were offered in 466 MHz, 533 MHz, dual 533 MHz, 667 MHz and 733 MHz configurations, the latter two using a newer PowerPC 7450 processor. The number of RAM slots was reduced to three, accommodating up to 1.5 Gigabytes of PC133SDRAM.

The 733 MHz model was the first Macintosh to include a built-in DVD-R or Apple-branded SuperDrive, the rest of the line became the first Macs to ship with CD-RW drives. This was also the first series of Macs to include an Nvidia graphics card, the GeForce 2MX.

At Macworld ExpoNew York on July 18, 2001, a new line debuted featuring a cosmetically redesigned case known as Quicksilver, and various upgrades to the specifications. It was available in 733 MHz, 867 MHz and dual 800 MHz configurations. The 733 MHz model was notable for not having a level three cache. The SuperDrive was offered on the mid-range 867 MHz model, and UltraATA/100 hard drives were offered on all models. The internal speaker received an upgrade, using a Harman/Kardon speaker.

Quicksilver received criticism in MacWorld's review for removing the 'eject' button and the manual eject pinhole, as well as the pass-through monitor power plug, and for the base specification of 128 MB RAM as being insufficient for running Mac OS X.^[6]

Updated Quicksilver machines, officially named Power Mac G4 (QuickSilver 2002), were introduced on January 28, 2002 with 800 MHz, 933 MHz and dual 1 GHz configurations. This was the first Mac to reach 1 GHz. Again, the low end 800 MHz model did not include any level three cache. The graphics in this series were provided by an Nvidia GeForce4 MX400 card. Some of these models have ATA controllers with 48 bit LBA for hard drives larger than 128 GB.

Mirrored Drive Doors/FW800[edit]

Another generation of Apple Power Mac G4s, officially named 'Mirrored Drive Doors' (MDD), was introduced on August 13, 2002, featuring both a new Xserve-derived DDR motherboard architecture and a new case design. All models were available in dual processor configurations running at 867 MHz, 1 GHz or 1.25 GHz. As with the Xserves, the PowerPC 7455 CPU used does not have a DDR frontside bus, meaning the CPU could only use at most 50% of the new system's theoretical memory bandwidth, providing no improvement over previous models. The rest was available to the graphics card and I/O systems. A single processor 1.25 GHz model would be the last Power Mac G4 the company offered to the public after the announcement of the new Power Mac G5, introduced in June 2003.

The last real update to the Power Mac G4 line was on January 28, 2003 offering dual 1.42 GHz PowerPC 7455 processors, with features not seen in previous DDR models: built-in FireWire 800 connector, optional integrated Bluetooth, and optional integrated AirPort Extreme. These were also the first Power Macs that could not boot into Mac OS 9.

With the launch of the Power Mac G5 on June 23, 2003, Apple re-introduced the August 2002 Power Mac G4 because of perceived demand for Mac OS 9 machines. Between that, its low price-tag, and the delayed availability of Power Mac G5s, it proved a strong seller for a relatively short time. Production stopped on June 27, 2004 and the remaining inventory was liquidated, ending the 20-year legacy of Classic Mac OS support with its discontinuation.

Timeline of Power Macintosh models

See also[edit]

Notes[edit]

1. ^'Apple Unveils 'Personal Supercomputer''. SFGate.
2. ^'Apple steps up to G4 Macs'. ZDNet.
3. ^'The 400 MHz PowerMac Reviewed'. The Mac Observer. February 21, 2000. Retrieved October 19, 2008.
4. ^'The Apple Power Macintosh G4 400MHz PCI'. Forevermac.com. Retrieved November 30, 2011.
5. ^'Power Mac G4 (PCI Graphics) - Technical Specifications'.
6. ^'Hands on with the Power Mac G4/867'. MacWorld. August 25, 2001.