The Core i5 wins in both :
Price - (Core i5 2500K:$220 USD; FX-8150:$280 USD, @NewEgg)
and Performance...
The FX-8150 was faster than the Core i5-2500K in only a few situations, and the performance difference was not so high as to justify the higher price you will have to pay to bring this new AMD processor home. So, unless you are a die-hard AMD fanboy, we think it is hard to recommend this CPU.
The Core i5-2500K is cheaper and provides a higher overall performance, and is the CPU we recommend for the user looking for the best price/performance ratio is the USD 200 - USD 220 price range. And if you really want performance, you can pay a little more and get the Core i7-2600K.
One of the only areas in which the AMD FX-8150 excelled was overclocking. We could easily set it to run at almost 5 GHz, and if you are into overclocking, with time and patience you will likely be able to break the 5 GHz barrier.
Source:
http://www.hardwaresecrets.com/article/AMD-FX-8150-vs-Core-i5-2500K-and-Core-i7-2600K-CPU-Review/1402/1Either chip you choose, unless you are running several virtual machines, or doing extreme computational tasks... I think they would both prove to be welcome additions to your environment. If AMD can keep their MTBF numbers up, I'm sure this architecture will only get better and more competitive (as long as the Core i7-3820 release next month doesn't completely kill off any remaining AMD positive press).