Hi I was looking to upgrade a system i built in late 2005, back then it was was using the latest mboard and components, but thus is the nature of technology that it is no longer so high tech. I was just looking to upgrade the processor and HDD at this stage, got no problems upgrading the HD but the processor poses a bit of a question. I was wondering whether an intel Q9400 Core 2 Quad, 2.66GHz would be compatible with a gigabyte motherboard with an Intel 945p express chipset and a 775 socket? and if not, would an Intel E8500 Core 2 Duo, 3.16Hz, be a better option?.
I looked at the Intel website and I believe it said that the Core to Quad was compatible with the 945p chipset, so would a core 2 quad have the same compatibility?
Thanks for anyone’s help 
“Core to Quad” is just a misspelling of Core 2 Quad.
doesn’t look like the Q9400 will be compatible with your chipset:
Intel® Core?2 Quad Processor Q9400 (6M Cache, 2.66 GHz, 1333 MHz FSB) with SPEC Code(s) SLB6B
same as the E8500:
Intel® Core?2 Duo Processor E8500 (6M Cache, 3.16 GHz, 1333 MHz FSB) with SPEC Code(s) SLAPK, SLB9K
check: Intel® 945P Express Chipset for a list of supported CPUs.
bear in mind that, whichever processor you go for, you’ll probably need to do a BIOS update to get it to work.
doesn’t look like the Q9400 will be compatible with your chipset:
Intel® Core?2 Quad Processor Q9400 (6M Cache, 2.66 GHz, 1333 MHz FSB) with SPEC Code(s) SLB6B
same as the E8500:
Intel® Core?2 Duo Processor E8500 (6M Cache, 3.16 GHz, 1333 MHz FSB) with SPEC Code(s) SLAPK, SLB9K
check: Intel® 945P Express Chipset for a list of supported CPUs.
bear in mind that, whichever processor you go for, you’ll probably need to do a BIOS update to get it to work.
oops, apologies for the double post, it was unintentional