Chosen Solution
Here’s me asking yet another question about this obsolete piece of history- I performed a CPU upgrade from the stock C2D T7300 to a T9300 so I could use the Dosdude1 patcher. There’s a slight problem though- the CPU reports as 400 MHz in “About this Mac”. Is this fixable?
I’m going to guess that the CPU is actually running at the correct clock frequency, but since MacOS doesn’t recognize it (this wasn’t a CPU that was offered with this computer), the speed is being reported incorrectly. I’d recommend installing a third-party tool like MacCPUID and trusting what that reports. Here’s an old answer post with some info about putting a T9300 in one of these older iMacs, there may be some useful info buried in there.
So lets look at the spec sheets to see what’s happening here: Core 2 Duo Processor T7300 (4M Cache, 2.00 GHz, 800 MHz FSB) Architecture series: MeromCore 2 Duo Processor T9300 (6M Cache, 2.50 GHz, 800 MHz FSB) Architecture series: Penryn So the CPU’s micro code held within the systems EFI (BIOS) is not able to support the Penryn logic. Clearly the Penryn 410 million Processing Die Transistors is a lot more than the Merom 291 million! The best CPU you can go with in this series is Core 2 Duo Processor T7700 (4M Cache, 2.40 GHz, 800 MHz FSB) Basically, you need to lookup what the series had referencing EveryMac to lookup the given system. Here this system is part of this series: iMac7,1
