Re: Help w/ MB and processor
A bottleneck is the lowest performing hardware on a system. Think when you are trying to pour out a bottle, the thing that limits the flow is going to be the bottleneck.
There is less than a 2% real world performance difference between 4x and 8x buses simply because todays video cards don't come close enough to using all the available bandwidth that the bus can offer. I have heard the analogy You can p*ss into a 4" pipe, or you can p*ss into a 8" pipe, the 4" pipe will not limit the flow any less than the 8" pipe will.
You said you got better performance on your TI4200. That tells me it's probably unrelated to your current hardware. I have the same monitor as yours, so you are likely running the same resolution as I am (1440x900), and I have worse specs than you (Athlon 2000+, 512MB RAM, GeForce 6800 on AGP 4x), yet HL2 runs just fine on my system.
If I had to guess, I would say your card is overheating and is underclocking to avoid burning up. My 6800 has this feature, so I'm guessing your 7800gs does too. So check your nVidia control panel and check the temps. It should tell you there if it's underclocking or not.
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