I'm putting together a new workstation and thinking of buying a Quadro K4200 GPU. I was wondering if there is a benefit to having two GPUs in either SLI configuration or not on a edit machine... Does an NLE even support SLI? What are your experiences with Quadro K4200? How does it perform playing back 4K footage? This is an offline machine but I want to be future proof for a couple of years. Thanks!

Quadro cards usually do not support SLI, don't know if this holds true for the K4200 too; if You plan using more than three monitors go for two cards, otherwise don't bother; a Quadro 4200 seems to be required for 4K playback, see http://avid.force.com/pkb/articles/en_US/compatibility/en365919 and You'll need outrageously fast hard drives; for an offline box I'd go for a K620 or a K1200, using proxies or an HD resolution to offline 4K stuff.

For the same money you could get a Titan X or Titan Black with 3 times the memory and massively better performance in other programs like Resolve.  It's not officially supported by Avid but it's a much better card for the money.  I'd be tempted to test it out.  Avid is notoriously bad at using the GPU for acceleration and with decent drives the Titan will speed through 4k stuff in Resolve.  I'd rather have a better all rounder than an over-priced, albeit officially supported, lesser card.

Andi

MC 8.4 seems to be pickier regarding the video card than previous versions, before suggesting an unsupported video card I'd do some reading over the forums. To cut a long story short: if You're an hobbist and love thinkering with Your computer go for whatever video card You like, while if You depend on MC to make a living and do not have time to waste troubleshooting go for a supported video card; running Resolve wasn't mentioned in the original question, but if that is the goal a K4200 should "suffice", while a twin card system can be set up, a Quadro for MC and a You-name-it for Resolve. And since we're departing from the original question I'd also give a look to the newly supported AMD cards.

I work as an assistant editor a lot at various post houses/ productions but I've been getting a more editing gigs on short films. Recently I cut a film shot on 35mm (transfered to ProRes 4444 - 2K) I have an old GTX 570 card & quadcore CPU overclocked to 3.6GHz now- works ok with some lag. I read about people "hacking" the "supported card file" in the Config folder of Avid. If I was to get a Titan or a better GTX card, would I be able to "hack" that "Supported GPU" text file and input new card info and driver? I do use Premiere quite a bit too for long form and short form work so I'm just trying to figure out what would be the best option... If I can do the "hack" thing with MC I think a Titan would be the way to go. But I definetly want a card that MC will support (mybe in newer versions of MC, they will accept/ utilize more cards like Premiere does).

Thanks for your help!

Could you edit the QualifiedGPUBoards file to add the Titan? Sure. But for 2K material I'm not sure you really need to. 2K is only slightly bigger than HD, so any system that handles HD well should handle 2K pretty well.

Of course the GPU wouldn't be just for HD/ 2K material... If i can edit the qualifiedgpuboards file then i think maybe a Titan X is more bang for the buck over the K4200 in Media Composer.

I think it comes down to the primary purpose of the system. If this is a dedicated MC system, then you're better off sticking wiith an approved board (search the forums for MonCon to look at the necessary and sometimes unworkable work-around to make GTX cards work with 8.3). If you  are using other software which is heavily dependent on the card's processing power (e.g. Resolve), then a GTX makes more sense. Just bear in mind that it won't necessarily work well with future versions of MC.