QX9300 Quad Core CPU in an iMac Early 2008 A1225

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QX9300 Quad Core CPU in an iMac Early 2008 A1225

Is this possible? On other forums, a user who had a 2008 iMac 24" with 3.06 GHz CPU with Nvidia Geforce 8800GS (same one I have) tried a QX9300 and it would not boot. My model number is an A1225 and the logic board is an 820-2301-A.

If not, what would be the "maxed out" CPU? Could the QX9300 CPU work with a firmware upgrade?

There really is limited information from what I can find. Either that means it you can't use a faster CPU or no one has tried it or felt it was worth it to try.

iMac, Mac OS X (10.6.8)

Posted on May 29, 2015 1:24 AM

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Answer 1

MichelPM

Level 10

80,952 points

May 29, 2015 1:56 AM in response to emuman100

I didn't think the CPU is removable. Usually, the CPU is soldered to the iMac logic board.

There is no way I know to do this and Apple does not provide any firmware updates for such a modification.

If this didn't work for a user who already tried this, it is not going to work for you.

iMacs have NO user upgradeable components or any way of changing the firmware that Apple now embeds the firmware and any ROM instructions directly into the CPU, now. There is no longer a dedicated ROM chip that you can Flash and change firmware or any other instructions, now.

I am pretty confident that what you want to do IS NOT possible.

Sorry.

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Answer 2

emuman100 Author

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1 points

May 29, 2015 11:05 AM in response to emuman100

The CPU is a removable socket P CPU. I took it apart when I repaired the video card. The QX9300 is also socket P, with a matching FSB frequency of 1066 MHz as the 3.06 GHz CPU already in there now. The service manual gives no specs on the motherboard.

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Answer 3

emuman100 Author

Level 1

1 points

May 30, 2015 10:32 PM in response to emuman100

A QX9300 CPU does NOT work in the 820-2301-A logic board. I ordered one, took eeeeeverything apart, cleaned off the old heat sink compound, put the new QX9300 CPU in, put on heat sink compound, put eeeeeverything back together, and it wouldn't boot. (I actually did it twice, because the first time I forgot to connect the CPU temp sensor and thought it wouldn't boot because of that.) Only two LEDs out of four came on. So I had to take eeeeeverything apart, put the old CPU back in, put new heat sink compound on, and put eeeeeverything back together. What a royal pain and time waster.

I suspect the reason why is because the firmware for the logic board only allows certain CPUs to work. That sort of thing seems to be common in hardware after the 2006 Mac Mini, probably to make you buy new hardware. I was able to upgrade the CPU in my 2006 mac mini and 2006 A1173 iMac to a 2.33 GHz Core 2 Duo that originally came with a single core CPU as well as a modified SMC loader to flash firmware that supported 4GB ram instead of the maximum of 2GB. So, if anyone wants to try this, don't. It doesn't work. Shame, because it would make for a nice machine with RAM maxed out.

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Answer 4

MichelPM

Level 10

80,952 points

May 30, 2015 11:04 PM in response to emuman100

I am not surprised.

After, say, 2005, Apple has made tinkering inside Macs pretty much impossible unless you have micro technologies background and even then, as you have discovered, being able to modify a Mac may not work.

Again, not surprised.

The days of modding Macs so you can get up to 10 years of service are behind us, now.

My theory is that Apple now designs hardware to last/fail (designed/planned obsolescence) between 5-7 years. A major hardware component needed for the basic operation of a Mac will fail where you have to make a decision to repair/replace an expensive component or be forced to use that repair/replacement money toward having to be forced into purchase either a new/refurbed Mac or purchase another newer, used model Mac.

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Answer 5

May 31, 2015 2:53 AM in response to emuman100

I would dare say the C2E CPU would have worked (Apple shipped one of these in an iMac of similiar age I think) if the system had a larger capacity power supply.

As the TDP of the original processor would have been far exceeded by this newer Extreme CPU, the iMac cannot boot as a large chunk of the power is being diverted to it and not enough to the other important system components that it requires to be active for use.

While it may be possible to get a replacement PSU I have no idea where one can be found nor have I read about anyone who has attempted it.

As for the maximum CPU that can go in that iMac I would look at a Core 2 Quad with the same Socket and TDP of your existing Core 2 Duo CPU.

Hope this helps!🙂

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