The 'Intel Core i7-3930K' will give you the best performance, it's benchmark of 12088 is significanly higher than the E3-1240v2 which has 9361 points.
» www.InstantDedicated.com - Online in no time » Dedicated Servers in [EU] Netherlands with DAILY support, also on weekends » DDOS Protected network - 100% Money Back if it doesn't work for you » Streaming / IPTV allowed | Up to 10 Gbit ports | 100% Network Uptime
As others have mentioned, using cpubenchmark.net will allow you to arrange the servers in most powerful to least powerful based on CPU performance.
ReliableSite.Net LLC - Offering Enterprise Grade Dedicated Servers Since 2006 [New York City metro / Miami, FL] Customers are our #1 priority - Read Our Reviews
Looking to switch providers? We have amazing deals and a 10 minute setup time! Click here to view incredible deals.
There isn't a huge difference between the 1230 and 1240, more so between the versions like v1 and v2. However the i7 will have the most performance out of all the servers. The i7 is desktop grade though while the E3's are server grade and built for 24/7 operation, usually ecc ram, etc. Just keep that in mind.
Difference is speed and 1240v2 have one additional technology:
Idle States (C-states) are used to save power when the processor is idle. C0 is the operational state, meaning that the CPU is doing useful work. C1 is the first idle state, C2 the second, and so on, where more power saving actions are taken for numerically higher C-states.