On the cpu thing, I just update when benchmarks show around double performance gain. Like here
http://cpu.userbenchmark.com/Compare...770K/617vs1537.
Check the server oriented benchmarks I think they are called Geek Bench.
Their take on the i7-950 "The i7-950 is a first generation Core processor which is now three generations and four years old. The 950 was included in the group test as a reference for how fast processors were back in 2009. "