Installing a Penryn in an iMac Alu... Side Effect

Hexus decided to disassemble an iMac Alu to replace the original Core 2 Duo Merom by the new high-end Penryn X7900 clocked at 2.8GHz.

If the installation was not an issue, the surprise came later on when checking the CPU and its performance: the FSB as well as the CPU are down clocked at 400MHz!
This is surprising if one considers that it was possible to upgrade iMac Core Duo with Core 2 Duo set on a FSB 667MHz without any problem. However, it is also possible that the CPU is not recognized (yet) by the motherboard, and consequently it boots in secure mode to avoid any over heating or high tension issue. With some luck, everything will be fixed when Mac OS X 10.5.2 will be released. Otherwise one will have to wish a hypothetical EFI update to make this CPU upgrade fully functional.