ATI Radeon 9600 Pro Mac & PC Edition: One Card for All

UI Performance

Mac OS X relies on a fully OpenGL accelerated GUI to, in a sense, make things look pretty (and enable features like Exposé).  But despite what you may think, the majority of UI performance is still dependent upon the CPU.  Until Apple enables Quartz Extreme 2D in Tiger, all UI elements are CPU rendered and, with the appropriate GPU, are simply treated as AGP textures and composed on the GPU itself.  Although the majority of the work is still done on the CPU, there is an element of GPU interaction that can impact performance. 

In order to measure the GPU's impact on overall UI responsiveness, we turn to XBench, a synthetic test that can give us a slight idea of UI performance.  The three tests that we focus on are XBench's Quartz, OpenGL and UI tests.  The latter is possibly the most important to UI performance, but all are interesting.

The Quartz test focuses on Quartz rendering performance and is mostly CPU bound, but as we mentioned earlier, there is a slight impact of graphics performance.  More than anything, we're looking at driver maturity here, since the test uses almost 100% of the CPU (it is only a single threaded test). 

The two 9600 based products are at the bottom of the charts, but not too far behind the Radeon 9800 Pro Mac SE and X800 XT cards.  NVIDIA's 6800 Ultra DDL continues to offer the best Quartz rendering performance that we've seen on any Mac platforms.

The OpenGL performance test is more of a primitive 3D test than anything else. It doesn't really impact UI performance at all - it's more of a basic texturing test as it makes no use of complex shaders. 

All of the ATI cards basically perform the same here, with the NVIDIA offering falling noticeably behind for some reason. 

The most interesting test is the UI test, which basically tests multiple UI elements and scrolling performance under OS X. 

When we first looked at this test, NVIDIA held a significant advantage over the fastest ATI offerings.  This time around, NVIDIA still has the UI advantage, but it has been cut down to just under a 5% advantage. 

The rest of the ATI solutions perform basically identical to one another, with the Radeon 9600 Pro Mac & PC Edition falling to the bottom of the list. 

With the synthetic benchmarks out of the way, let's look at some games...