Best Graphics card for HD video Editing

Hi, I have trawling the internet for months and found nothing relating consumer graphics cards to their video editing potential, every single review is about gaming.

I want to know, which of these two would be better for HD video editing at 1920x1080i resolution?

GTX 470

or

HD 5850 2GB Toxic edition

Btw, I am planning to CF or Sli (then possibly tri-fire) in the future, so that must be a consideration.

If anyone has benchmarks could you please post them please? (even if they are about unrelated cards but to do with video editing)

I am using Pinnacle studio which cannot use CUDA, however the main application I use within that is Magic Bullet Looks, which can use CUDA. This is why I am confused as to which one to get. Will CUDA have a significant effect on the speed of rendering and real time previews?

For video editing you will surely need the CUDA technology......so you'll have to do with a NVIDIA GPU>>the GTX 470 is more apropriate for video editing...

and yes CUDA have significant effect on quite any things!!

you can also use Super LoiLoScope Mars or TMPGEnc Xpress

A single "simple" video card like an 8400GS or an HD 5750 is more than enough for video editing. You don't need CUDA unless you will specifically use a video editing program than utilizes CUDA and most don't.

You won't need SLI or Crossfire. Why introduce extra heat or power issues when video editing is all about CPU horsepower.

I use two different PCs just for video editing, one with a Q9400 and one with an AMD hexacore Thiuban 1055T. The Q9400 has the simple 8400GS videocard (no fan) and the AMD has the 5750 and both cards are more than enough to hook up 2 two monitors to each.

Looks is a specific case and a bit buggy to say the least being very poorly coded for OGL acceleration, this has been an issue since about 2008, and one when you had to trade off better quality in ATi or Matrox for better speed in the Geforce cards.

Things have improved somewhat (be sure to update your drivers for either ATi or nV), but right now the way it handles transforms it is still slower on the ATi cards than on nVidia. If you use Looks on an regular basis that will be an issue, for others like Boris, it's the other way around.

d_95 is a little myopically simplistic, although in your case the nV card would be better, but that's not always the case, not by a long shot, especially as they move to more universal acceleration like OpenCL and Direct Compute which greatly favour ATi for video editing, especially with a little help from SAD (Sum of Absolute Diff) transform math added to the shaders.

Since you already have an HD4850, then it doesn't make as much sense to move to another ATi card than it would to move to an nV card simply because you can easily fall-back should you change the apps you use, and the card you have is already pretty powerful for thos apps that do offer global acceleration. You will likely find the nV card better in some things like MB Looks and the ATi better in others.