Agp 0x vs 4x

i have an old agp card (sig) and the agp bus is set to 0x. It used to be set to 4x, but my gpu kept shutting down at that. I would like to know what the difference is in a game like quality, fps vs having it at 0x.And my gpu is the only thing overclocked, and its not going over 70 degrees. The black screen shuts off 15mins into the game even though the cpu is on. Then the gpu goes into vpu recover and the process starts over again. My psu is a bit underpowered, but i took out every component that is unneccessary.

Bump!

Hmm. Generally you should be able to set the bus to 4x with no problems. What PSU do you have? I doubt that's the problem here, but I'm curious.

Have you tried installing the latest drivers from AMD/ATI?

You sure the problem isn't the GPU overheating at higher workloads? Have you checked to see if the heatsink/fan have loosened or are otherwise compromised?

The heatsink and fan are perfect in place!
My psu is the crap dell 250watt and i am supposed to have 350.......
But there is no sign of underpowered psu because when the gpu shut off, my cpu stayed on and vpu recover opened.
Can a gpu be simply overloaded so that it shuts down?

And yes, latest drivers. And one question that wasnt answered is what would be the main performance difference?

GPUs can crash if they get low power. It may not trip the (nonexistant in your case) OL protection in the PSU, but the power might be unstable enough to cause the GPU to lock up and the driver to restart.

The AGP bus is how the rest of the system transfers data to the GPU. If it's slowed down, there's usually some performance hit, but in general it's not a huge difference. Running at 2x should probably be about the same as 4x with that card. 1x instead of 4x might bring a ~10% performance hit, or more. I'm just guessing here.

If the system runs ok with the lowest AGP setting, then I would just leave it there and call it good.

Thanks for the help people.
I found it good enough for me at 0x but maybe in the future i will pick up a cheap antec psu that is enough wattage for my old dell.
Then i can probably oc a bit higher due to the extra wattage because i turned the clocks down on the gpu because of the psu.