CS:S stress test only running 60 fps

I have a good computer, but I'm only running on 60 fps on a Counterstrike Source stress test, when people with crap rigs are running at 200+. Here's an example: http://www.neoseeker.com/forums/41305/t1505110-whats-yo...

And here's the relevant information:
i7 920 DO @ stock
BFG GTX 260
EVGA SLI LE 1366 mobo
Corsair DDR3 6GB running @ 1333 mhz (haven't run it up to 1600 rated yet)
Corsair 750W PSU

I did just build this about a month ago, never made any tweaks or overclocked anything. All I've done is flash the BIOS, flash my SSD, and get the latest stable drivers for my GTX 260.