try another gfx card in there and see,,,,just think of something and try it. just do a whole lot of different combinations and you will see something whats wrong
what is the spec of the gf's pc, obviously they are not the same and video ram on a gpu does not mean it is a good card ie 256 can easily beat 512 depending on bus
silent hill gives me this error: ABORTING build [FINAL] v6.34 Changelist: #663064 Silent Hill: Failed to create pixel shader because we ran out of video memory. Try decreasing the quality settings.