Sometimes yes, sometimes no. You can't know for sure until you try or someone tells you your specific cards will work together because they've already tried that combo. As a general rule, you want ALL of your video cards to run from the same driver... though sometimes 2 drivers from 2 makers will work together... And sometimes different model cards from the same maker won't work together... I had one years ago with ATI cards... wouldn't run all from same driver, so installed 2nd ATI driver... hosed up my system so badly I had to reinstall the OS from scratch. Video card driver conflicts can be very destructive, though not always. Be wary of "3rd party" cards and OEMs in dual/multi card setups...
UPS just arrived with 3rd and 4th monitors. No time until this evening to install. My wife saw me running into the office with 2 boxes, wish me luck with both "issues"
"Number of monitors" (up to OS's capacity... and depending upon the computer) is not an issue. Video card driver(s) always is. My primary trading rig runs 5 monitors... all works "smooth as a gravy sandwich"... Some ETers run as many as 8 monitors.
It sounds like you have already found a solution, but we often recommend to our Cobra Trading clients that they just buy a USB to VGA external video adapter. You can get them directly from Dell and it is made by Star Tech. They are only about $50. It's not as clear as a new video card, but it's external and it takes about 1 minute to install. Hope this can help someone. Happy Trading!
Ok. Took a little while, but we're up and running. Had to update NVIDIA drivers online, and it took a little screwing around with the configuration to get the mouse lined up when moving from screen to screen.Not completely satisfied, yet, with the resolution of the larger screens, but I'll work on it. Scata(?) you were right about the diff. drivers. The ATI recognized the new cards, but was not able to control them. The NVIDIA control panel works fine.
I can spread my losses across 4 screens. Not to mention the Daily Hottie thread......yeaaaaa boooyyyy!!!