TrustedReviews has posted an AGP Graphics Card Group Test - they tested the BFG 7800 GS, the Leadtek 7600 GT, the Inno3D 7600GS-AGP and Sapphire X1600 Pro. Here's a taster:

On our very high test settings, Call of Duty 2 was barely playable on any of these cards. The Sapphire X1600 Pro was the fastest though. Of course, if you lowered the gameplay settings, it will run, so this is still a good relative indication of performance. Unfortunately, because it was running so slowly, it would cause the machine to fall over - so we only got results at 1,280 x 1,024. I was getting some strange artefacts with the 7800 GS that may be why the results are so low.

Quake 4 had a natural affinity towards the nVidia cards, due to a considerably better OpenGL implementation and support for UltraShadow II. The X1600 Pro was trailing behind at almost half the frame rates of the 7600 GT and 7800 GS. What was most interesting, was how the 7600 GT was keeping up with the 7800 GS and in many cases beating it. It seems the higher clock speeds make up for the extra pipelines and 256-Bit memory interface significantly.

Counter-Strike: Source showed a similar trend to Quake 4, with the 7800 GS and 7600 GT constantly battling for first place. Even the 7600 GS was performing admirably, although trailing behind when the FSAA and AF settings increased. Once again, the X1600 Pro was seen in last place by a significant amount. When FSAA and AF settings were increased, the X1600 Pro was hit a lot less than the 7600 GS, so won a lot of the better image quality settings, but unfortunately the frame rates were drastically low.

Both Battlefield 2 and Prey showed exactly the same trends. 3DMark06 summed things up nicely, with the 7800 GS and 7600 GT getting an almost identical score, and the 7600 GS and X1600 Pro getting an almost identical score. At 1,920 x 1,200, we see the 7600 GT performing faster than the 7800 GS, and the X1600 Pro coping a lot better than the 7600 GS.