Depends on the game. Some titles are massively CPU bound, some run the logic somewhat asynchronously which can be a fit fugly but CPU still helps smooth it out in them too.
Timedemo benchmarking hides the importance of the CPU as it can more easily fetch the required code, data, and knows in advance which way an if statement is going to go, etc.
I know of several titles that would gain linear performance increases on that CPU.
PS: The HD6950 GPU overclocks well, and it may have come with better GDDR5 memory than it's reference design, so the video memory may overclock too. It is certainly not a bad video card, it's just a little dated. I still run a less powerful video card than that myself.