I have developed a specialized fluid hydrodynamic simulation, using the approach called “direct numerical simulation”, DNS. This requires the fewest assumptions, but, until recently, was regarded as completely intractable. The holdup is solving the Poisson Equation by relaxation.

The code was developed using Visual Studio on Windows 7. It is completely CPU bound, not memory intensive. The holdup is solving the Poisson equation. I developed a multi-threaded, recursive multi-grid algorithm, the so-called V-Cycle. It isn’t fast enough. I run it on an AMD Phenom II at 3 gHz.

I first investigated AMD, and bought a 4870x2 card, but their Open Cl platform seems stuck in beta, with loud cries of bad performance. It is possible to get speed out of it if one is prepared to work hard close to the metal, but it seems like too much work, considering the impending transition to Open Cl. The current Nvidia environment is much more refined, but I’ve heard that a factor of 10 improvement over a multi-threaded multi-core CPU approach is questionable.

I have preordered a C2070 card, but that may not show up for nine months.

Suggestions on what to do in the meantime would be appreciated. In single precision, what factor of improvement could be expected solving the Poisson equation by relaxation with multi-grid, in a typical grid size of 20000 ? Perhaps with a GTX295 card?