Matrox's Parhelia - A Performance Paradox

One of the biggest drawbacks to the Parhelia architecture is that it contains no significant occlusion culling technology for the early rejection of pixels that won't be seen by the user before they are rendered. In order to test how much this costs the Parhelia we dusted off Villagemark, a benchmark with an incredible amount of occluded pixels that shouldn't be rendered if your GPU is smart enough to realize that. Provided that your GPU can't, it's in for a bit of a render test.

Memory Controller Performance Villagemark @ 1024x768 NVIDIA GeForce4 Ti 4600 Radeon 8500 Matrox Parhelia 96 93 71 | 0 | 19 | 38 | 58 | 77 | 96 | 115

Although Villagemark is an extreme case, we see that the Parhelia is definitely hurt by this. The fact that Parhelia is "only" 26% slower than the GeForce4 in Villagemark gives hope that the lack of occlusion culling technology won't hurt it too much in today's games.

For synthetic performance we chose 3DMark 2001SE with the latest 330 patch applied. We don't put much weight on the 3DMark tests but we can get some useful information out of them:

The Parhelia comes away with a higher fill rate than any of the competing solutions but if you'll notice, the triangle throughput of the GPU is the worst in the high polygon count benchmark with only 1 light. This changes when the complexity of the scene is increased with the use of 8 lights instead as the additional vertex processing power of the Parhelia is able to shine.

Despite the superiority the Parhelia exhibits on paper, we are not able to see that translate into noticeably higher scores in any of the vertex or pixel shader tests.