I have a 2009 Mac Pro (Mac Pro 4,1) and I'm using two DVI monitors on my Radeon 4870 right now. Those are two 20" 1680x1050 monitors. However, I'm editing video a lot using FCP X and I'ld like to add a 32" or 40" LCD to my setup to (pre)view my video's in 1080p. I think I have two options here: 1. Replace my Radeon 4870 with an Radeon 5870 (5770 works two but has trouble with noisy fan on 2009 Mac Pro.) This is an expensive upgrade + I will need to by 2 MDP -> Dual Link DVI adapters according to this Apple KB article: http://support.apple.com/kb/HT4279 2. Install a second graphics card. Something like a Nvidia GT 120. The second option is way more wallet-friendly. But I heard that using a second graphics card can make FCP X slow/unstable. Does any of you have experience with this?