[2009 Mac Pro] From dual to triple monitor setup

[awenger]

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?

 

[lemonade-maker]

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?

I don't know about fcp running slow with dual cards but I run four monitors with a gt120 and a 285 with no issue.

 

[minifridge1138]

Go for the GT120.
A lot of people will say it's weak but it will be get the job done (and then some).