View Full Version : G5 1.8 upgrade to G5 2.3

Feb 26, 2008, 02:16 PM
Hello all!! I just bought a G5 mac tower with dual 1.8s. I also purchased a pair of 2.3s and the power supply from dual 2.3 as well. Can I just drop the new processors into the slots and have them work?? Is there anything I need to do to facilitate this upgrade?? Any help would be appreciated!!


Feb 26, 2008, 02:37 PM
You need the 2.3 motherboard... something about the G5 firmware locking you in. The bus speed is not adjustable, therefore the CPUs won't run at 2.3GHz.

I recall someone trying to do this, but it threw off thermal calibration and put his fans at a constant full-blast, and the CPU speed wasn't what he hoped.

Feb 26, 2008, 02:43 PM
Thanks for the heads up, Aibo

Lord Zedd
Feb 26, 2008, 10:40 PM
He is right, this isn't like the old G4 where you could throw in a new CPU card and everything would be fine and dandy. The G5 CPU is tied to the motherboard now. Even if you remove the CPUs and don't put them back the same (You put CPU1 in slot 2 and CPU2 in slot 1 for example or replace one of the CPUs with a different one) you must use an Apple Service Diagnostic CD to recalibrate the thermal controls.

There will likely never be a CPU upgrade for the G5, you're stuck with swapping a bunch of parts between different chassis.

Basically, if you want a 2.3 you're better off selling your 1.8 and buying a complete 2.3 than swapping parts.