I’ve just built a budget system ($400) i5 2500k, GA-H61MS2H for Windows 7 and Mac Lion 10.7.3 because our i7 920 1366 x58 motherboard died. To replace a new x58 motherboard would run me about $120 – $200 and the system will hog over 189W when I encode a movie, it was fast but I don’t know if it’s worth it to spend ~ $150 for an old system. The current Intel best sellers are the Sandy Bridge i5 2500k and i7 2700k. I5 2500k has 4 cores only 4 threads and 6MB cache instead of 4 cores 8 threads and 8MB cache of the i7. The price difference right now is about $110 for the CPU. My son will be playing games on this computer and I checked it out with the bench marking, it’s great with i5 2500k, i7 2700k is 100Mhz faster than the i7 2600k (FYI).
H61 chipset vs Z68 chipset
Z68 chipset supports USB3 and SATA 6GB.
I’m going to build a overclocked i5 2500k + Asus P8Z68-V LX LGA 1155 Z68 for less than $300. now ($169 CPU + $59 Motherboard + $29 8GB DDR3 1600) .