Big framerate drop using second video card

Hi everyone,

been doing a few upgrades to my meager desktop setup since I've a bit more space now than I did before. I added another video card(Radeon HD5450) and a new monitor. so now I have a monitor below my main scenery display as well as one off to the side for charts and the like.

I was initially running the instrument display off the new video card until I realized that I would drop from my normal framerates to 1-5 FPS I have now switched the setup so that the main video card runs both of the main FS monitors to try to avoid this. I also found through testing, that this problem only seems to occur when running the sim on Windows XP. and will occur even if just running a window on the secondary video card. Windows 7 doesn't experience this.

I have tried updating the drivers since those are usually the culprit to video problems. No dice this time though

I would like to occasionally put instruments such as the gps onto the chart display but with my current difficulties this is impossible. Does anyone have any ideas as to how to remedy this?

Not a solution for your problem, but a note about two graphics cards. If you use a PCIe 16X port for your primary card and then you add an additional card to your system, both PCIe slots can drop down to 8X (depending on motherboard). If this makes a real difference in rendering, I do not know. But since it cut the memory bandwidth in half it might. Would be interesting if someone with some knowledge of these things could share information. For this reason I bought one card instead of two.