CrossfireX things to know?

[cammil334]

I'm trying to completely understand the pros and cons of Crossfiring two cards, specifically 7970's. I want to do this since I'm doing multimonitor but I keep getting mixed results of "It's great and you get great performance out of both cards." to "You lose half the performance on the cards so its not worth it". I want the help of the good people of the forum to figure this out because its confusing the hell out of me. How exactly do you get the best performance of the two cards.

[Maskot]

Do it.

[WoodenMarker]

You overclock them and make sure they get good air circulation.

Enjoy your performance

[Hazy125]

Pro's-

More performance on GPU bound tasks

Better aesthetic appeal

 

Con's-

You lose half the VRAM. For instance, two 2gb cards only gives 2gb of usable VRAM not 4

There aren't many programs that fully utilise 2 graphics cards

Two cards don't give you exactly double performance, maybe only 50 percent extra

You get microstuttering which is especially true for AMD cards

[laxer]

When you crossfire the card only the primary card works as an output device...

 

So if you wanted to run more than 4 monitors you would need to disable it and use the other card...

 

I currently run Xfire 6970s and love them...

 

Performance in games varies though...

[cammil334]

Two cards don't give you exactly double performance, maybe only 50 percent extra

So i would get most of the performance of the first card and half of the second card?

[Hazy125]

Scaling is near 100 percent on pretty much any sli/xfire setup with the last few gens and micro stuttering is all but gone come the new drivers coming out soon

also theres actually very few games that won't take advantage of two cards. You only really find issues once you hit 3 or 4 cards.

I was thinking about more than 2 cards really

 

So i would get most of the performance of the first card and half of the second card?

 

The exact same way you get the most out a single card solution, overlcocking

[cammil334]

The thread was about crossfiring 2 cards?

Yes. Sorry I wasnt specific.

[Hazy125]

Yes. Sorry I wasnt specific.

Exactly as @marto said, I'm just slow

[SteepGnomeKing]

Here's the way I see it. You are wanting to CF 2 7970's, very nice powerful cards. Not everything works with CF/SLI because of compatibility but those are smaller games that don't need 2 cards anyways so you can disable one when playing that game and still get your 60/120 fps depending on what monitor your using, the other is new games for a little till profiles get introduced and than all works fine. 

 

The scaling from what I've seen and observed is good. Everything that you would want CF for has nice scaling. All the new triple A games have nice new engines and are very compatible. Crysis 3 had ~80%+ increase from CF/SLI.

 

New drivers are being released for Frame Rating and there's Radeon Pro out right now to help with that issue. I honestly don't know how bad it was but I never heard anyone complain about stuttering frame until this news from pcperspective was released and all of a sudden it was the worst thing ever. People who CF on the forums don't even compalin and say they don't notice anything.

 

New drivers 'should' be out on the 31st supposedly to help with the frame rating issue to smooth it out. But you will always want the newest drivers anyways. But I'm an early adopter kind of person when it comes to software and like the beta's and the alpha's.

 

Your main card, the top one, will get hotter because of a more restricted air flow to the fan(s) but not enough that it is going to require you to down clock if you are overclocking. 

 

I'm all for SLI/CF I am looking to get my second 680m here soon before they disappear for good. They make a big difference and will hold you off for a couple more years till you have to start lowering your setting lower and lower till the point you'll want new cards. I think it is a good investment even if your gaming at 1080p because if you like AA it will make a big difference having that second card to have the power to back that up.

[cammil334]

Here's the way I see it. You are wanting to CF 2 7970's, very nice powerful cards. Not everything works with CF/SLI because of compatibility but those are smaller games that don't need 2 cards anyways so you can disable one when playing that game and still get your 60/120 fps depending on what monitor your using, the other is new games for a little till profiles get introduced and than all works fine. 

 

The scaling from what I've seen and observed is good. Everything that you would want CF for has nice scaling. All the new triple A games have nice new engines and are very compatible. Crysis 3 had ~80%+ increase from CF/SLI.

 

New drivers are being released for Frame Rating and there's Radeon Pro out right now to help with that issue. I honestly don't know how bad it was but I never heard anyone complain about stuttering frame until this news from pcperspective was released and all of a sudden it was the worst thing ever. People who CF on the forums don't even compalin and say they don't notice anything.

 

New drivers 'should' be out on the 31st supposedly to help with the frame rating issue to smooth it out. But you will always want the newest drivers anyways. But I'm an early adopter kind of person when it comes to software and like the beta's and the alpha's.

 

Your main card, the top one, will get hotter because of a more restricted air flow to the fan(s) but not enough that it is going to require you to down clock if you are overclocking. 

 

I'm all for SLI/CF I am looking to get my second 680m here soon before they disappear for good. They make a big difference and will hold you off for a couple more years till you have to start lowering your setting lower and lower till the point you'll want new cards. I think it is a good investment even if your gaming at 1080p because if you like AA it will make a big difference having that second card to have the power to back that up.

Awesome. I'm not getting the cards for a few months so those drivers should be here by then.

 

With 3 ASUS VG248QE monitors at 144Hz and 1ms response times will the cards be powerful enough to be able to play games on highest settings getting at least 90 or more frames?

 

I dont really care about micro studdering since I've gotten used to it with my current system but can it become a noticable problem?

 

The airflow will be good since I'm not having the cards stacked right on top of each other and may switch to watercooling in the future.

 

Is it difficult to disable the second card if I need to?

[SteepGnomeKing]

With 3 ASUS VG248QE monitors at 144Hz and 1ms response times will I be able to play games on highest settings getting at least 90 or more frames?

 

I dont really care about micro studdering since I've gotten used to it with my current system but can it become a noticable problem?

 

Is it difficult to disable the second card if I need to?

 

With no AA I'd think so. Something like BF4 I'd think something around 85+ at all times.

Not sure haven't experienced it my self before but since your not getting it for awhile I assume it won't be it will be fixed for the most part.

Don't know about AMD but I assume it's like Nvidia in the sense of going into the CCC and click a button to disable it. Quite easy. Don't have to take it out or unplug the power or anything.

[beefalo]

Awesome. I'm not getting the cards for a few months so those drivers should be here by then.

With 3 ASUS VG248QE monitors at 144Hz and 1ms response times will the cards be powerful enough to be able to play games on highest settings getting at least 90 or more frames?

I dont really care about micro studdering since I've gotten used to it with my current system but can it become a noticable problem?

The airflow will be good since I'm not having the cards stacked right on top of each other and may switch to watercooling in the future.

Is it difficult to disable the second card if I need to?

I use 7970s in crossfire. Getting 90+ fps at max settings will be possible in eyefinity but will be tough to do in some games. I use eyefinity and crysis 3 I get about 50 at medium texture resolution and high graphics. Far cry 3 blood dragon I can max at 60 though. Pretty much anything but crysis you should probably be fine.

I've never really noticed micro stuttering but it does seem smoother with radeon pro. Screen tearing I think is more of an issue but those 144hz monitors should help prevent that. One issue most people don't mention is one of your monitors will have a very noticeable scan line. Its not a big issue in landscape eyefinity but it becomes annoying in portrait.

[SteepGnomeKing]

I use 7970s in crossfire. Getting 90+ fps at max settings will be possible in eyefinity but will be tough to do in some games. I use eyefinity and crysis 3 I get about 50 at medium texture resolution and high graphics. Far cry 3 blood dragon I can max at 60 though. Pretty much anything but crysis you should probably be fine.

I've never really noticed micro stuttering but it does seem smoother with radeon pro. Screen tearing I think is more of an issue but those 144hz monitors should help prevent that. One issue most people don't mention is one of your monitors will have a very noticeable scan line. Its not a big issue in landscape eyefinity but it becomes annoying in portrait.

 

What is your monitor set-up 3-way surround?

[beefalo]

What is your monitor set-up 3-way surround?

3x1080p portrait eyefinity.