7970 Crossfire + Vsync on (Does it work?)

[csaris]

Hi there guys, I'm looking to upgrade from 2x580s in SLI to 2x7970 in CF.

I have 3x1080p 23" TN panel monitors with DVI outputs and I'm wondering if someone can tell me for sure if the vsync on option works with the 2x7970s and 3 monitors so I can proceed.

The reason I ask this is because with the 2x5870s & 2x6970s the vsync on option would not work at all and as a result I was getting lot's of ms when the fps were on the 60-70 zone.

With the 2x580s the vsync on works flawlessly though and locks ata 60fps.

Thanks.

[ViciousXUSMC]

I have only had dual 5870 for about a month but I have not had any issues using vsync, so not sure that problem is still out there or why it was an issue in the first place.

Maybe your thinking of forcing it via hardware level, that perhaps does not work. But at the software level in game I know it does and would assume it would work also with the 7970.

[tepescovir]

Wouldnt mind confirmation on this as well. I have used dual 5970's, dual 5870's and a combination of the 2 last year and finally gave up and bought 2 580's as i was sick of the stutter and vsync issues with ati and eyefinity. All would work fine on a single monitor, but always had visual tearing even when i could get vsync to work with d3d over rider and stuttering in most games.

So have they fixed this completly?

[ViciousXUSMC]

If you had tearing in eyefinity mode with vsync on that sounds like "the line" issue.

I used to have it but I have not seen it in a long time. If I overclocked my cards it was much worse so I think just backing off to stock clocks is what did the most good for me.

For me it was almost always just a single monitor out of the 3, also the 5870 only could support 2 monitors on non DVI so one 3rd monitor needed an active DP adapter if you were not using native dP so that also maybe plays a small part in why it was one monitor out of 3.

[Haldi]

i got two HD7970 here, so what Game and What Settings are we Talking about ?

[csaris]

Thanks for all the answers guys but I'm asking for something specific.

I'm not talking about a single card or tearing.

I'm asking if somebody that has 2x7970s EF with 3xDVI monitors to confirm if the vsync on option works and LOCKS the fps at 60 or not.

@Haldi

Can you please confirm with the 2x7970s in EF mode if you force ON the vsync option ingame to lock the fps at 60?

And also which monitor outputs are you using?

Thanks

[X3R Kefran]

I received my two 7970 saturday. Here is the situation for me in Eyefinity:

- With V-sync on, I got random crashes (freeze with no possibility to go back to windows - restart needed). (note: I first thought, on of the two cards had an issue but after several tests, they work perfectly individually)
Examples: Assassin's creed Revelations, Batman Arkham Asylum, F1 2011 (systematic crash at the beginning of the benchmark)

- With V-sync off, I do not have the crashes but in most games, the framerate is not as smooth as the FPS indicates. The perception of smoothness is aften better with one card even if Fps tell the contrary.

Globally, it seems that drivers do not yet manage correctly "7970 crossfire + eyefinity" and it is worse with V-sync.

We need to wait next drivers.

[Wijkert]

I dont want to sound pessimistic, but it is possible that AMD might never release drivers in which eyefinity+crossfire doesn't result in microstuttering (or at least not in the near future). Have you considered to run just one 7970 and return the second card? How was the microstuttering with 2 580?

[Jza]

I received my two 7970 saturday. Here is the situation for me in Eyefinity:

- With V-sync off, I do not have the crashes but in most games, the framerate is not as smooth as the FPS indicates. The perception of smoothness is aften better with one card even if Fps tell the contrary.
Globally, it seems that drivers do not yet manage correctly "7970 crossfire + eyefinity" and it is worse with V-sync.
We need to wait next drivers.

He is spot on.
On my 6990
Vsync on - wasn't smooth at all so its useless
Vsync off - 60fps felt more like actually only 40fps.
I tried everything to fix it. I was so angry that I had dropped so much $$$ on the perfect eyefinity card that couldn't do it's job properly.
A mate came round to my house to plug his Sli gtx 570's into my 3 screens and it was a smooth and beautiful thing... It was enough to make me cry ><
Here's is how I fixed it:
I promptly sold my 6990 and Bought a new 7970 with a Waterblock on it and overclocked the shite out of it.
Crossfinity is a bad idea.

[XxOsurfer3xX]

This is good to know, I was thinking of buying a second 7970 for my 3x1 portrait... I think I might switch to nvidia camp...