With the launch of Steam for the Mac, a lot of attention has been focused on the relative performance of Mac gaming. Early benchmarks have shown that the same Steam games run at a significantly slower framerate under Mac OS X than under Windows.

The reason for the discrepancy has been described as due to relatively immaturity of drivers on the OS X side as well as other slowdowns. Some modest improvements may be seen with the upcoming release of Mac OS X 10.6.4, but more dramatic improvements remain in the pipeline.

Responding to concerns about performance on some Mac Steam games, Valve employee rbarris provides some reassurance that further performance updates will be coming:

Performance is going to improve as drivers are updated. I would expect modest improvements in short term and larger ones in longer term. No, I can't put dates on them. We are making a lot of progress is identifying specific issues that need work inside the game and inside OpenGL and drivers. Apple, ATI and NVIDIA are all involved.

Steam is said to be working with Apple, ATI and NVIDIA on these optimizations for improved gaming performance. Driver-level features should arrive over time with future Mac OS X updates.