Large fluctuations in FPS and choppy gameplay

[napes22]

Foxconn C51XEM2AA- 8EKRS2H
AMD Dual Core 4200+ (AM2)
2 Gigs Corsair DDR2 PC6400 Ram
Enermax Liberty 500W
Sapphire 1800XT (w/ uFormula VF1-PLUS Cooler)
Western Digitail Raptor HD

So far it happens in all HL2 core games. I will get FPS up to around 170, that will almost immedately drop to 30 and below. Using the stress detector on CS Source, it showed a constant FPS of 60. While the fps fluctuates I experience extremely choppy gameplay. What could be the cause? It is very frustrating, becuase I spent a bunch on this rig so that I would be able to play games like this without overheating/bad fps.

Thanks.

 

[robkas]

when you have HL2/CSS open minimize and open your task manager.

Right click on the game process and there should be something like "SET CPU AFFINITY" or under "SET PRIORITY"

anyways..find CPU affinity somewhere and disable one of the cores and your game should run much smoother

 

[napes22]

Oh my, constant 100 fps now...thanks so much. Why does it do that with multiple cores enabled?

 

[robkas]

i don't know, probably because the source engine is amazing, and was made amazing when single core cpus were the only things out. so something in dual cores must offset the engine.

i don't even know if that is partially correct...but that is my explanation lol

 

[napes22]

hahaha, thanks a lot. Much appreciated..saved me a lot of hair.

 

[Zap]

Doesn't look like it from your avatar.

 

[BassBomb]

I thought they got patched for dual cores eventually with steam...