fixed pipelined lighting slow on newer hardware

Hi, I have an application written in 1.x days. The performance has been acceptable for its purpose until lately we are getting complains from users about it being slower with newer hardware supporting 3.x and up. I believe it is the lighting that is causing the slowdown. Anyone has similar experience and idea how to address it?

Thanks in advance,


which cards? (manufacturer, I mean)
we’re actually getting much better ffp performance than custom shaders on modern nvidia quadro’s.

On both NVIDIA and ATI.

It’s possible that fixed function lighting may not be optimally implemented in newer hardware. I know for a fact that it’s the case for fog (which may be software emulated in SM3 or above hardware) so it’s reasonable to suppose that as other fixed functionality gets further deprecated, the implementation may suffer.