Sockets and CPU compatibility

Acrylik

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Jan 10, 2012
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This may seem like a dumb question, but I can't find a "Yes" Or "No" Answer to this anywhere. If I have a Pentium processor that works in a LGA 775 mobo socket, would it also fit in a LGA 1155? I know a sandy bridge wouldn't work in a 775, but would something that fits in a 775 also fit in a 1155?
 
#1 - The CPU's socket type must match the motherboard's CPU socket type. This means an Intel socket LGA 775 CPU will only fit in a motherboard that is also socket LGA 775.

#2 - Just because the CPU and motherboard have the same type of socket (like LGA 775) does not always mean the CPU and motherboard will always work together. Older LGA 775 motherboards may not recognize newer LGA 775 CPUs. The newerr LGA CPU may physically fit, but if the motherboard's BIOS cannot recognize what CPU is installed the PC will not start.

Example - One of my PCs is built around an MSI 975X Platinum Power Up edition motherboard works with a dual core Intel Core 2 Duo E6600 (It now serves as a home theater PC). However, it does not recognize the Core 2 Quad Q9450 which I used for my next PC. The Q9450 (a 2nd generation Core 2 Quad CPU) can be physically installed in the MSI motherboard, but it's BIOS will not recognize it nor is there an updated BIOS from MSI that would allow the MSI motherboard to recognize the Q9450. Thus, I needed to buy another motherboard that would recognize the Q9450; Abit IP35 Pro. I already knew this and my plan was to have two PCs anyway.
 

Maxor1

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Dec 12, 2011
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With the Intel processors that likely is completely true. I have seen however more than a couple of cases of various AMD Athalons and Phenoms that aren't specifically supported by a motherboard, working in that motherboard which supports the same family/number of cores. I'm pretty sure that you aren't getting optimal performance out of them but they will load and post and boot. The OS may call the processor what it really is or what the bios thinks it is but cpuz has in every-case I've seen gotten the processor right. This isn't something I recommend doing but if you are Frankensteining old computers, or getting strange deals on parts.