Firestrike 17669
Score17669 with NVIDIA GeForce GTX 970(2x) and Intel Xeon Processor X5670
Graphics Score
23729
Physics Score
14702
Combined Score
6764
...and just realised my RAM is running at 533mhz. Must have put the multiplier down when I was testing 210. Will sort that and try again in case it makes any difference.
OK so I just ran it with my rig. 3970x @ 4.7ghz with two Titan Black running EVGA SC bios. These are at stock, I know they overclock well. Results -
Score - 18639
Graphics score - 23583
Physics score - 16719
Combined score - 7767
So I think it's quite honestly safe to say that a hex core Xeon on X58 is more than man enough to game with, running modern cards in SLI.
Personally I would spend on GPUs, not a CPU upgrade.