We at SUSE needed to know whether we had some severe regressions regarding graphics performance during enablement of intel SandyBridge graphics - and it turned out that it was not commonly understood what graphics performance is actually composed of. Some were only interested in core X commands (xterm users :-) , some only in render performance (office users :-) , some in low-core 3D graphics (compiz users :-) , some in hardcore 3D graphics (gamers :-) .
So finally I put together a standardized graphical benchmark with aspects for all users. And no, it won't output a single number, because that would be meaningless for everybody. But it makes it easy to compare different aspects between different graphics cards and drivers, and there are some surprising results. But more about the results later.
The sources for the benchmark are now on gitorious, and the Wiki entry describes its usage. It's currently somewhat tailored to SLE11SP1, so you might run into minor issues when running it on a different OS version. And of course, it's not very polished yet .