HD 4850x2 / crossfire

[-EVRE-]

I'm still a bit confused after reading posts on these forums about ATI's crossfire and its x2 graphics cards.

Recently my main box stopped recognizing my 8800gt (card is fine, working in my sisters box O.o) So I have been demoted to my 7800GT's *ouch* :p
So.. I'm on the upgrade warpath and I need some clarification as to what works, what dont.

The HD 4850x2 looks like its a very sweet video card, it stomps the GTX280.. etc etc..

However I read that to use the 4850x2's other two DVI ports you must disable crossfire. This means WoW is running only on a single 4850?
however... LegitReviews.com has an article on the card and I quote "..... don't forget about the added ability to utilize those (4 dvi ports) without having to toggle between CrossFire modes!"

I intend to run 3 monitors, a 30" monitor 2560x1600 and two 19" monitors 1280x1024 for my three accounts.
I want the 30" to run maxed out, like I did with the 8800GT
I'm willing to plunk down for a GTX260 216core or GTX280 and get a dualhead2go or a 4850x2. Depending on the decision of Nvidia/ATI determines what motherboard I buy SLI/Crossfire

Current Idea for a build:
Phenom II Quad Black edition 3.0
GeForce GTX 260 Core 216, GTX280 or 4850x2
8gb ddr2 1066
MSI DKA790GX Platinum (crossfire) or MSI K9N2 Diamond (SLI)
850watt corsair PSU

SO.. bottom line, go Nvidia or 4850x2 to run 3 monitors?
(I want to know from personal experience if the performance of the 4850x2 is maintained while running 3 monitors)
pinotnoir, I guess this one is for you, you told me crossfire works for multiple monitors.

[pinotnoir]

You cant run 3 monitors crossfire or sli. What you do is plug all 3 monitors into the card and run it. If you want to play Crysis or something just click crossfire and use your main monitor. I have the 4850x2 and its very nice. I can turn on crossfire and use two monitors. One twist though is I use one monitor in portrait mode. This puts the stop to crossfire with 2 lcd. If you dont invert your LCD you can crossfire 2. Running 3 just plug them in to the dvi's and play. Your choice to run 3 is buy two cards, buy the 4850x2 which can run 4 monitors, or buy that triple head go which I think is a waste.

[-EVRE-]

just to clarify then, when not using the crossfire mode, are all 3 monitors dependent on the performance of a single 4850 chip? I have ALOT of pixels to push. 6,717,440 to be exact O.o

*edit*
answered my own question

The 4850x2 is an awsome card, but its not for me :( a single 4850 gpu doesn't even come close to enough grunt, and I'd be wasing a ton of money on the x2.

pinotnoir, I bet the 4850x2 is a great card, but I believe the only way for me to get the graphics grunt I need, I'll need to buy a dualhead2go to split the DVI port. one for the 30" and one split in two (or three with the triplehead2go). That way I dont run into the issue of having the system push the video through the second video card. My experience with that was with my 8800GT and a 7800GT, I actually got worse FPS running two monitors.

*edit edit*
I could use the 4850x2 if it is happy to run with only 2 DVI ports active and a dualhead2go to get maximum performance from the card. Crossfire will work this way with WoW right? (in the case of the x2 gfx card?) or for more grunt the only ATI option the 4870 1gb?

[pinotnoir]

From what I understand about the card if you are running 4 monitors its like two 4850 1gig cards but its running off 1 card. For more information I would check sapphires website. The card is more than enough power for world of warcraft. If you play fps games you can take full advantage of the card and crossfire. Do what makes you happy. It's working great for me. I switched to boxing 5 on 2pc. With the expansion my q6600 system couldnt handle running 5. My 4850x2 card runs two monitors on my i7 920 system. I capped the max fps at 50 and my game play has never looked better. You can buy the triple head go but to me its a waste of money. For me, the question is, why spend the money for additional hardware when all you have to do is plug in your monitor to the dvi? So far for me it works fine.

[Clanked]

If you were using an 8800GT to power your 30" you should be fine with the 4850.

The card has 4 outputs, two for the first card, two for the second.
Please someone correct me, but if you put the 30" on the first DVI port, and then your two 19"ers on ports 3 and 4, they would be running off of seperate cards.

I don't think a single 4850 would have any trouble running a 30" screen.

[not5150]

The 4850x2 is basically two 4850 cards glued together. Two outputs are connected to one card, while the other two outputs are connected to the second card.

The card comes with Crossfire enabled by default so you'll pull your hair out for hours wondering why you can't get the third and fourth monitor to work. Just go into Catalyst control center and disable it.