The S3 Graphics driver for Linux is still proprietary (though its kernel module claims to be GPL) but it did introduce OpenGL 3.0 support along with VA-API acceleration for GPU-assisted video playback. We have not been able to test this new Chrome 500 series Linux driver, but a site called "Chrome Center" has tested out the Linux and Windows drivers.
Chrome Center's Stefan had ran Nexuiz on both Linux and Windows to compare the performance of a S3 Graphics Chrome 430 GT. His processor was an AMD Phenom II. His results show that the S3 Graphics Linux driver is actually faster than their Windows driver.
Stefan concludes, "I don't actually know if the Linux driver is that good or if the Windows driver is that bad... I will do a few more benchmarks to investigate this further." In an email to us, Stefan has mentioned that he is looking to use the Phoronix Test Suite for additional S3 Graphics tests.