The open-source support for the R300 series had to be reverse engineered (for more information see ATI Has Open-Source Drivers Too) and as a result there remains much room for improvement with this driver, but their performance overall is much higher. In this test we had used an ATI Mobility Radeon X300 64MB (running at 1400x1050) with an Intel Pentium M 750 (1.86GHz) and 2GB of DDR2-533 memory running Fedora 7 Test 4 and the X.Org 7.2 Radeon driver.
In this environment while idling on the desktop Beryl Benchmark was reporting 60~65 FPS, but once we started utilizing the Beryl water effects and other eye candy the frame-rate had dropped to 15~20 FPS. At this rate, the desktop wasn't lagging nearly as bad as the Radeon 9250, but there is of course much room for improvement. AMD/ATI Radeon graphics cards that are from the R300 series or newer are generally able to cope with Beryl on the desktop without any serious issues.