I understand crossfire allows you to have 3 or more monitors.
Does it increase graphics performance?
If I had two graphics cards in crossfire would i have double the RAM and video speed?
How does it work?
Answer by Vadrotan · Jan 23, 2013 at 09:28 PM
Crossfire is using 2 to 4 AMD GPU's to improve gaming performance. You do not need Crossfire to enable 3 monitors, you simply need an HD 5000 series graphics card or newer; for example, I am currently running a single HD 7970 and I have 3 1080p monitors hooked up to it. As far as the RAM is concerned the graphics cards do not share RAM between them, so two cards with 3GB of RAM apiece are not the same as one card with 6GB. Furthermore the performance does not simply double or triple the more cards you add, two cards in Crossfire will net you 150 - 200% performance depending on the game and driver support, 3 cards will net you closer to 200 - 250% performance and four will net you something around 300%. Those percentages are definitely just rough estimates, but there are most certainly diminishing returns involved in multi-GPU set ups. Generally speaking the best and simplest thing you can do is buy the best single card you can afford now and if necessary in 6 months or a year buy second.
Everything I've said here more or less applies to Nvidia's GTX 600 series graphics cards, prior to the GTX 600 series you do need 2 or more Nvidia GPU's for 3 or more monitors.