In need of a good graphics card for OpenGL

I’m working on some old software and need advice on what graphics card I should get to make it run as fast as possible. The application is written in VB6 and uses a 3D graph control from the Measurement Studio package made by National Instruments. I’m fairly certain it uses OpenGL for rendering, hence why I’m asking here. We used to use NVIDIA cards, but about a year ago, the NVIDIA cards stopped working with the control (the frame rate dropped a ton, and we tried using older drivers). We’ve since switched to ATI cards, but it still isn’t as fast as we want it. So any suggestions on graphics cards? Maybe some that specialize in OpenGL rendering?

Well nvidia cards are already the best for opengl rendering…
What models exactly do you have / had ? Drivers version ?

Ideally tracing the ‘old software’ to check what features it actually uses will help a lot. If you don’t have the old software source code, you may use this tool :

Thanks for the info on glintercept, I’ll try it out and see what I can find. Here is a post I made a while back on the National Instuments forum:

I have an application that uses a CWGraph3D to plot data that is usually 300 x 300 data points. It used to work fine, but I’ve recently bought a computer with a nVidia GeForce 7600 GT and another computer with a nVidia GeForce 7900 GS, and the graphs plot so slow that the application is unusable. I also have another computer with a nVidia GeForce 7800 GTX and it runs fine. If I swap in one of the other video cards to this computer, then the application is unusable, which makes me think the graphics card is the problem. Is there any documentation that says what kind of graphics cards should be used so that the graphs will work? Is there a way to get the graphs to work with these graphics cards other than turning off hardware acceleration?