AGP speeds

[B-MAn]

i heard that if i change my AGP speed from x8 to x4 the sound stuttering will stop on HL2 but how much of a performance impact will the drop in speed have in general? I have a Geforce 6800 ultra and on my bios it says my APG memory is at 64mb, should i change this to 256?

 

[Nex321]

By changing x8 agp to x4, it will give you about 3 fps drop