Although Apple would like you to believe that the smoothest road to a faster Mac is paved with the latest iMac, Power Mac G4, iBook, or PowerBook, purchasing a new computer every few months is hardly within the means of most Mac users. If a new Mac is likely to bust your budget, consider a processor upgrade — an add-in processor card that can make your applications run faster, windows open and scroll more quickly, menus flash down in an instant.
Although you can find processor upgrades for Macs made during the latter days of the Reagan administration, Macs introduced prior to the mid-1990s aren’t worth upgrading — compatible processor upgrades for those ancient warriors are terribly sluggish by today’s standards. However, just about any PowerPC-based Mac can be fit with some variety of G3 upgrade, and many will accept G4 upgrades.
Processor upgrades are available from such companies as PowerLogix (512/795-2978,
), Sonnet Technologies (949/587-3500,
), and XLR8 (800/513-9744,
) and range in price from just under $200 to over $1,000 for dual-processor G4 upgrades.
If the process of actually installing the upgrade, rather than price, is holding you back, allow us to allay your fears. Our step-by-step instructions will show you that upgrading your old Mac with a new processor is dead easy.
Equipped with no more than a Phillips-head screwdriver and a grounding strap we’ll show you how easy it is to install a processor upgrade in a common collection of Macs — a blue-and-white Power Mac G3, a beige Power Macintosh G3, and a Power Computing PowerTower.
Contributing Editor CHRISTOPHER BREEN pens
The blue-and-white G3 and Power Mac G4 are a cinch to upgrade thanks to the drop-down side door and a processor that’s easily accessible.
Install any software necessary to make the upgrade work. Such software generally comes in the form of an extension and control panel combination that allows the processor’s faster cache settings to kick in. Your processor may also include a utility that helps the upgrade work with Apple’s latest firmware upgrade — an upgrade that may interfere with the operation of the processor upgrade.
If you’re installing a G4 processor upgrade into your blue-and-white Power Mac G3, you’ll need to apply a firmware update to your Mac (this update is included with the upgrade). The update overwrites the Mac’s ROM so that the motherboard can accept the new processor. While applying such an update is rarely a problem, recent firmware updates from Apple that disable RAM that’s out of Apple’s specifications demonstrate that firmware updates can be a one-way street — once you install the update it can be difficult, if not impossible, to revert to a previous firmware version.
Thankfully, makers of processor upgrade cards are working on utilities that will return your blue-and-white’s firmware to a previous version.
Switch off the Mac without unplugging it (leaving the Mac plugged in helps with grounding issues), remove any external cables that might get in your way, and pull open the side door. To avoid zapping your Mac with built-up static electricity, string a grounding strap between your wrist and the Mac’s power supply (if you don’t have a grounding strap, touch the power supply (A) to discharge static electricity).
Locate the G3 processor and detach the heat sink by pushing down and out on the heat sink’s clip (B).
Lift the handle (C) next to the processor and gently lift the processor (D) from the ZIF (Zero Insertion Force) slot (E).
If the new processor includes a heat sink, remove the original heat sink, which you previously detached from your G3’s processor. Insert the new processor (being careful to align the pins properly), crank down on the handle, and close the Mac.
Beige G3 Tower
It’s a bit more difficult to get inside a beige G3 than a blue-and-white G3, but once inside, the ZIF slot makes it nearly as easy to upgrade the processor.
Unlike with the blue-and-white G3, you must remove all the cables from the beige G3 Tower to open it. After installing any software necessary to make the upgrade work, remove the Mac’s side panel by pressing on the green release button (A) and pull up on the panel.
Use a grounding strap or touch the power supply to discharge static electricity, flip up the locking handles (B), and pull open the case (C) to reveal the motherboard inside.
Remove the clip that holds the heat sink in place, pull up on the handle to unlock the processor, and gently lift out the old processor.
When replacing the processor, line up the processor’s pins so that the corner of the processor that’s missing a pin (D) matches the blank spot on the ZIF slot (E).
Older PCI Power Mac
You can add a processor upgrade to any Mac that bears a processor direct slot (PDS). These include the Power Macintosh 7500, 7300, and 7600; the 8000 and 9000 series; and most PowerPC 604-based clones.
How you open your Mac depends on the model — see your Mac’s manual for instructions. On our Power Computing PowerTower 180e we removed four large screws to detach the outer case and then unclipped and removed an internal fan (A) to access the processor card. A Power Mac 7600 requires that you press a couple of tabs at the bottom-front of the case to remove the Mac’s lid. You may need to detach cables to open your Mac.
Likewise, where the processor resides in your Mac model is likely to vary from our instructions, but the general process for removing the old processor and inserting a new one applies.
After installing any software necessary to make the upgrade work, discharge any static buildup with the grounding strap or a touch to the power supply. Locate the processor card (B) (it can be identified by the large heat sink (C)) and pull straight up on the processor. When adding the new processor be sure that the tabs on the bottom of the card line up with the tabs in the processor direct slot.