Postby The GoldFish » Sun Oct 05, 2008 1:40 am
the GeForce 5 series (FX) and Radeon 9### range was pretty much the first big technology specification arms race of the long lived DirectX 9. nVidia lost, badly, by totally overshooting the spec, (they got their own back with SM3.0 in the 6 series), the consequence of which is that the whole FX range has broken pixel shader 2.0 support. Unfortunately for nVidia card owners, pixel shader use sky rocketed, resulting in the cards being pretty much universally slated.
Interestingly, Dar/Multiwinia barely even uses pixel shaders during common gameplay, if at all, and even if it did they're unlikely to be SM2.0. The game is in opengl too, so, really, by the virtues of performance history, the FX cards should pretty much be as good as or better than the (otherwise) equivilent ATI card of that generation.
I'm not 100% certain, but I don't think this is the problem you're looking for.
The 5700 and 5500 were late, budgety additions to the range, and, though I may be wrong, I think they've been causing issues with the Darwinia engine for quite a long time.