My old computer that I built out of parts in 2011 is starting to have the CPU overheat. I've tried a new case fan, but that was no help, so I'm thinking of just replacing it with a refurbished business desktop from Newegg or Amazon. Right now I have an Athlon II Propus 640 quad core CPU with 8 GB ram in 2 4GB Ripjaws DDR3 SD1333 memory sticks, running on Windows 7 home premium 64 bit. The performance is still fine on my old machine for uncharted waters online and emails, but I want to get either an i-core 3 or i-core 5 with 8 GB memory and stick with win7 64 bit. My question is, will the old memory units work with the newer computer if it has 4 slots? Are all DDR3 memory chips compatible?
Side question - I saw a test of 10 CPU's and the Celeron Haswell was doing quite well even compared to the i3 and i5 in some tests - what's up with that? Should I consider celeron?