We have 40 different Intel e5420 "cores" spread across eight rack machines. These machines are about five years old. The application is scientific computing, specifically a kind of single threaded Monte-Carlo simulation.
When we move to a new office very soon, we would like to replace all these machines with a single one (or two). I strongly suspect a single machine like this HP ProLiant DL585 is much more than twice as powerful as the current setup, but I don't really know how to cook up a back-of-the-envelope comparison. I'd like to be able to announce: It will be about 3.2 times as fast. The example HP machine has four AMD Opteron 6300 Series Processors.
I understand comparing CPUs (and mainboards) can't necessarily be reduced to a one metric apples-to-apples thing due to various differing characteristics, but what's a good rule of thumb? How could I do the math with readily available information to make sure some machine I buy is at least as powerful as 40 Intel e5420 cores?
More specifically, anyone got any server recommendations? We're looking to spend about $10K for as much CPU power in a single machine as possible. It'd have to run on a 110V line.