lag issues - not what you think

[Marcellus]

So I just built a new computer. Bf2 runs great, I can run crysis at 1680x1050 almost flawlessly. Cs 1.6 lags. Horribly. On any server I join, I start lagging. I'll lag (my screen will stutter) for a second, maybe two seconds, then I'll move for about 2 or 3 seconds, almost as fast as if I was speed-hacking. Then I lag again, then speed-hack speed again, and so on. It never gets better, no matter how long I stay in a server. I've tried different screen resolutions, different video quality settings, different cmdrate/updaterate/rate settings, set my max_fps to 101, looked at net_graph 4 with no signs of choke or loss. I've reinstalled steam/counter-strike several times. I have no programs running in the background, no downloads, and the firewall is not the issue either. Dxdiagnostic shows no problems on my system. Anyone have a clue as to what the problem might be?

My computer:
biostar ta770 a2+
amd 64 x2 4400+ @ 2.3ghz
a-data pc6400 2x2gb ram
sapphire hd 3870 512mb/256bit graphics @ 775mhz

I really appreciate any help I can get!

[CaRnAgE!]

you have done everything i think everyone else would do. thats quite a stumping problem. if you can run crysis, there is no way your computer would have trouble running 1.6, so idk what you can possibly do.

[Marcellus]

I fixed the problem by changing from openGL to D3D.. will I see any performance differences?

[CaRnAgE!]

i dont even know what openGL or D3D is... but hey, if it works...