I have researched this and there appears to be no advantage to using server processors over desktop processors for minecraft unless using out-of-game features like dynmap or other plugins which run on their own threads enough so to justify buying more cores. You could even call it a disadvantage because of the wasted money. Although MC uses around 63 threads its still mostly a single threaded engine. It seems like having more than 4 cores is completely pointless, and the real bottleneck is CPU and RAM clock speeds. Server processors are meant for when you have a very large number of threads and need as many processing cores as possible, while MC will almost never utilize more than three.
I recommend getting a high clock speed quad core such as a Vishera for only 120$ and liquid cooling and overclocking it to around 4.5GHz, which would be nearly twice as fast as processors people use and for 1/5 the cost.
I may be wrong however, but everything I've read and experimented points to this. --Khlorghaal 04:28, 10 May 2013 (UTC)