X-bit labs

Intel Graphics Media Accelerator 900 and Intel 915G: New Generation of Integrated Graphics (page 4)

Category: Chipsets

by Tim Tscheblockov

[ 07/12/2004 | 09:12 AM ]

Synthetic Benchmarks: Pixel Performance

Thanks to the four pixel pipelines and increased clock rate, the pixel output rate and the texturing speed grew manifold on GMA 900 compared to the previous core, Extreme Graphics 2. The fill-rate tests of 3DMark 2001 SE confirm this fact:

Intel’s GMA 900 is very close to its maximum theoretical texturing speed, both when rendering one and several textures – the texturing speed is 80% and 96% of the maximum, respectively, in the hardest mode.

The share of read/write operations with the frame and Z buffers is much higher at single-texturing than at multi-texturing, so the tile-based GMA 900 processor, employing caching of the Z-buffer and the frame-buffer, should be similarly efficient at single- and multi-texturing. It is a notable fact that GMA 900 has a higher efficiency at multi-texturing, though, which is a trait of classic-architecture GPUs. At the same time, in spite of the limited memory bus bandwidth, this GPU is rather indifferent to the changes in the precision of the frame buffer, Z-buffer, which is a feature of tile-based processors.

Now let’s see the new graphics processor handling pixel shaders. Specialized test suites like Xbitmark or ShaderMark wouldn’t run on GMA 900, finding no hardware support of vertex shaders, so we’ll limit ourselves with the results of 3DMark 2001 SE and 3DMark03 only:

Like all modern graphics processors with hardware support of DirectX 9 pixel shaders, GMA 900 finds it no problem to do DirectX 8 shaders. It runs a simple DirectX 8 shader fast enough, being just a little slower than the RADEON 9600.

The efficiency of Graphics Media Accelerator 900 declines at rendering a scene with a more complex shader. Considering the difference in frequencies between the RADEON 9600 and GMA 900, I can say that GMA 900 is nearly twice slower. On the other hand, it keeps its advantage over the GeForce FX 5200.

Running a complex DirectX 9 pixel shader, rich in mathematical calculations, the new graphics core from Intel finds itself behind the GeForce FX 5200, not even mentioning the RADEON 9600/9550.

So, GMA 900 is quite efficient at texturing but execution of complex DirectX 8 and 9 pixel shaders doesn’t seem to be among its strong points.