Far Cry - HDR
Far Cry was the first title to adopt High Dynamic Range (HDR) rendering via floating point blended surfaces, however its support was specific to NVIDIA's range, as these were the only boards with such capabilities when it was implemented, which limited use on the new X1000 series. However, CryTek, the developers of Far Cry, have implemented a patch that not only changes the engine to support ATI's floating point blending capabilities, but also adds the capabilities for Multi-Sampling FSAA with HDR.
| Far Cry - HDR - Normal (FPS) | 640x480 | 800x600 | 1024x768 | 1280x1024 | 1600x1200 |
| XT - Normal | 100.4 | 100.2 | 100.2 | 100.0 | 98.8 |
| XT - HDR | 92.0 | 91.2 | 78.0 | 51.8 | 35.5 |
| XL - Normal | 100.2 | 100.1 | 100.2 | 99.2 | 91.2 |
| XL - HDR | 89.4 | 83.1 | 66.8 | 42.8 | 28.0 |
| % Diff Between Normal and HDR: | 640x480 | 800x600 | 1024x768 | 1280x1024 | 1600x1200 |
| XT | -8.4% | -9.0% | -22.2% | -48.2% | -64.1% |
| XL | -10.8% | -17.1% | -33.3% | -56.8% | -69.3% |
Enabling HDR in this Far Cry patch creates a fairly drastic performance impact on both the X1800's, basically wiping off two thirds of the performance at high resolution, although the performances are more acceptable in the mid resolutions.
| X1800 XT - Far Cry HDR (FPS) | 640x480 | 800x600 | 1024x768 | 1280x1024 | 1600x1200 |
| Normal | 92.0 | 91.2 | 78.0 | 51.8 | 35.5 |
| 2x FSAA & 4x AF | 90.8 | 86.4 | 65.1 | 43.0 | 28.1 |
| 4x FSAA & 8x AF | 90.8 | 83.4 | 61.0 | 40.6 | 26.2 |
| 6x FSAA & 16x AF | 89.9 | 75.2 | 53.0 | 35.4 | 22.7 |
| % Diff from Normal | 640x480 | 800x600 | 1024x768 | 1280x1024 | 1600x1200 |
| 2x FSAA & 4x AF | -1.3% | -5.2% | -16.4% | -17.0% | -20.7% |
| 4x FSAA & 8x AF | -1.3% | -8.6% | -21.8% | -21.6% | -26.1% |
| 6x FSAA & 16x AF | -2.3% | -17.5% | -32.0% | -31.7% | -35.9% |
Once the initial performance drop for enabling HDR has occurred the further performance reduction for HDR with FSAA (and AF) enabled aren't that great on the X1800 XT, with 6x FSAA reducing the performance by 36% at high resolutions, despite the fact that there are 6 times as many floating point samples being written.
| X1800 XL - Far Cry HDR (FPS) | 640x480 | 800x600 | 1024x768 | 1280x1024 | 1600x1200 |
| Normal | 89.4 | 83.1 | 66.8 | 42.8 | 28.0 |
| 2x FSAA & 4x AF | 86.7 | 71.5 | 49.3 | 32.3 | 23.1 |
| 4x FSAA & 8x AF | 84.4 | 65.9 | 45.6 | 30.5 | 19.5 |
| 6x FSAA & 16x AF | 77.1 | 56.3 | 38.8 | 25.8 |
| % Diff from Normal | 640x480 | 800x600 | 1024x768 | 1280x1024 | 1600x1200 |
| 2x FSAA & 4x AF | -3.0% | -13.9% | -26.3% | -24.6% | -17.5% |
| 4x FSAA & 8x AF | -5.6% | -20.7% | -31.8% | -28.8% | -30.3% |
| 6x FSAA & 16x AF | -13.8% | -32.2% | -41.9% | -39.7% |
The X1800 XL displays similar trends to the X1800 XT, however with more samples the performance hit is a little greater due to its reduced bandwidth. Here we can see that the size of the FP16 buffer and 4x FSAA pushes some data out to system RAM reducing the fill-rate performance at 1600x1200. The 1600x1200 frame buffer size with 6x MSAA samples is such that the 256MB X1800 XL doesn't render this mode.
