HDR: A Costly Thing, a Work for SLI
Since those who enable high dynamic range lighting are looking for extreme image quality, we enabled maximum level of anisotropic filtering as well.
Wow! The performance impact is just unbelievable and is more than 50%. High dynamic range requires tremendous memory bandwidth and quite some additional computing power from graphics processor and its memory subsystems, even high-end graphics cards of today cannot handle that load. Therefore, we should expect games to acquire that technique only when the next-generations of graphics processors will get 24 – 32 pixel pipelines and advanced memory interfaces. No need to tell that RADEON 9700 would show dramatically low framerate with HDR enabled.
NVIDIA GeForce 6800, HDR vs RGB Rendering
Even though HDR works slow, there is a cure for that slow work even now. Multi-GPU technology like NVIDIA SLI would probably help to boost the speed. Of course, you should have a dual NVIDIA GeForce 6800 Ultra or GT installation and you should consider carefully whether $1000 for a graphics sub-system worth an improvement in FarCry.
Still, putting aside some drawbacks with implementation, with HDR enabled you’ll get absolutely the best image quality and realism available today.