i know the thread is old - but i have the exact same problem as this guy: http://www.techsupportforum.com/f59/...ag-241265.html
with my amd athlon 64 x2 dual core 6000+. I lowered the cpu voltage from 1.4 to 1.35 v and the cpu speed from 3 ghz to 2.6 ghz, and this worked for me to. But this isn't a great solution when my fps is lowered too.
I've googled this "lag spike" problem and found out that i'm not the only one who has this irritating lag.
I have 8800gt 512mb, 4 gb of ddr2 ram, asus m2n mx se mobo >>550W PSU<<
So - i think it's my power supply that is causing the lag. But anyone knows about this problem, or can recommend a good psu to my system?