Apple took a nice step forward when it introduced the first Aluminum iMacs (iMac7,1) in August 1997. The logic board uses the Santa Rosa chipset, and it has an 800 MHz data bus, up from 667 MHz on earlier Intel-based iMacs. The CPU sits in a socket (Socket P), so you can upgrade it!
When upgrading, be sure you get a CPU designed for an 800 MHz FSB (Front Side Bus), as Socket P CPUs also come designed for 533, 667, and 1066 MHz FSBs.
This is not the same socket used in 2006 iMacs. Socket P was designed for mobile CPUs, which Apple often used in iMacs to keep power consumption and heat down. This is generally considered to be a difficult model to upgrade.
UPDATE: If you want to run macOS 10.13 Sierra, you must install a CPU with SSE 4.2. These are 2.5 and 2.6 GHz chips, so not as fast as the 2.8 GHz Core 2 Extreme, but they will late you run a more modern Mac OS. See CPU Upgrades So 2007 iMacs Can Run High Sierra for details.
Socket P iMacs, 800 MHz Bus
Numbers after the model are 32-bit single-core/32-bit multicore/64-bit single-core/64 multicore results using Geekbench 3.
- 2.0 GHz Mid 2007 20″ iMac, 1093/1914/1173/2077
- 2.4 GHz Mid 2007 20″and 24″ iMacs, 1286/2280/1382/2461
- 2.8 GHz Core 2 Extreme Mid 2007 24″ iMac, 1465/2606/1601/2893
These iMacs use “regular” Core 2 Duo CPUs, and the 24″ Mid 2007 was also available with a Core 2 Duo Extreme. Here are the ones you might use when upgrading:
800 MHz Bus Socket P CPUs
- 2.0 GHz Intel T7300 Merom Core 2 Duo, 35W draw
- 2.4 GHz Intel T7700 Merom Core 2 Duo, 35W draw
- 2.8 GHz Intel X7900 Core 2 Extreme, 44W draw
iFixit reports that the 20″ iMac can support the higher power draw (44W vs. 35W) of the Core 2 Extreme CPU.
You can search on Intel’s website to get more data on CPU upgrade options. After you get to this page, select Family: Legacy Intel Core 2 Processors and Sockets Supported: PGA478. For the 2007 iMacs, select Bus Speed: 800 MHz FSB, because you don’t want to use a CPU designed for a slower or faster bus. This will provide you with an extensive list of CPUs that fit the socket as well as important details such as power consumption.
Keywords: #mid2007imac #cpuupgrade #socketp
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