Quick question for those with Crossfire and Freesync

[ICDP]

I bought one of the recent R9 Nano cards on offer with he aim of making a mini ATX cased gaming PC. While I am getting the parts for that together I am using the Nano in Crossfire with my Sapphire R9 Fury (non X) on my Samsung U32850R Freesync monitor.

The problem is that as soon as I enable Freesync with Crossfire the games take a massive FPS hit and mouse lag becomes unbearable. For example with Crossfire enabled and Freesync off Rise of the Tomb Raider sits at 55+ FPS at 4K mostly max settings. As soon as I enable Freesync the FPS tanks to 34 FPS and moue lag makes the game unplayable. In single GPU mode the same setting get me 28 FPS.

Same for Dying Light. pegged at 60 FPS almost constantly but as soon as I enable Freesync the FPS tanks to 34 and the lag becomes unbearable.

Is this normal behaviour? I would prefer the benefits of Freesync as well as Crossfire if that's too much to ask.

 

[ICDP]

Turning off frame pacing helped a bit in Tomb Raider but still getting around 30% less performance with Freesync+Crossfire compared to Crossfire without Freesync.

Dying light is just a complete no go with Freesync and Crossfire. 34 FPS and horrendous mouse lag there. In Fallout 4 I get massive stutter with Crossfire and it's far more playable with single GPU. It doesn't work in any of my flight sims either though it's what I expected to be honest from multi GPU.

It really takes a special bread of sadomasochist to willingly inflict Crossfire upon themselves as a long term viable solution.

 

[ICDP]

I have been trying and failing to find a solution to why my Crossfire FPS tanks when Freesync is enabled.

I made it to the Geothermal Vents level in Rise of the Tomb Raider and in one part I get the following FPS at 4K.

1 GPU (R9 Fury 1050): 26FPS
With R9 Nano as second Crossfire GPU (No Freesync): 45 FPS
With R9 Nano as second Crossfire GPU (Freesync enabled): 36 FPS

Frame pacing off or on makes no difference. So from 73% scaling to 38% scaling is quite a drop. This is all on the latest Crimson Drivers.

Witcher 3 and Dying light drop from 50+ FPS at 4K mostly high settings to 34 FPS and generally stay at 34FPS. It's almost like enabling Freesync and Crossfire at the same time is adding some sort of vsync with the associated lag.

 

[ICDP]

Hi, my names tommy, Iv'e been clean for 9 months 3 weeks and five days now!

Lol, this kind of crap from MGPU is not new to me to be honest. I am really pushing myself to get the mini ATX case sorted so I can go back to single GPU bliss

Just find it all very odd.

 

[ICDP]

If you can, try and hold on for hopefully a solid Polaris delivery and just go single mate.

I felt your pain and chucked it after years of happy mgpu gaming, I couldn't take it any more after (the best AMD mgpu driver ever)Omega, absolutely made my 290X's destroy everything I threw at them.

Then killed my hopes stone dead with the ~4 month driver drought as I was hammering into various mgpu titles with zero profiles but FC4 was main game at the time and the best I could get my 290X's running was with home made profiles that detracted from the experience(glitches)-frustration kicks in, most of the time I just used single gpu and by the time the first working FC4(second fixed profile) profile arrived, I'd finished the main game and frustration kicks into overdrive.

The final nail was when the CDPR W3 AMD can't be optimised for GW's announcement aired-I sold up

Frustration no more now, it's just plain sailing now on single.

I am of the same opinion and am happy with Fury non X performance at 4K with Freesync. I am happy to compromise on graphical options and even resolution if performance is required.

I just thought I would try Crossfire since I have the Nano sitting waiting on the rest of the parts for my mini ATX build.

 

[ICDP]

Are your core clocks fluctuating when this occurs?

Yes they are but even with clockblocker keeping clocks static the problem occurs with massive FPS drop using Crossfire and Freesync concurrently.

I also get the same issue with Heaven 4.0 which gives around 15% performance loss when enabling Freesync + Crossfire compared to just Crossfire.

For reference I get anything from 15% to 50%+ performance loss just enabling Freesync along with Crossfire.

Another Update

I used Display Driver Uninstaller to remove the latest 16.1.1 FO4 Hotix drivers and installed 15.11.1b drivers (last CCC drivers pre Crimson). I tried these with Dying Light and they work perfectly with Freesync+Crossfire enabled. The FPS is identical in Crossfire with and without Freesync enabled. Same for Heaven 4.0.

So it seems to be a Crismon driver related issue.

P.S Dying light with Crossfire and Freesync at 4K is just awesome. Really makes me see what Crossfire can do when it works.

 

[ICDP]

Good man, that was going to be my next piece of advice. The clock fluctuation issue is not present in 15.11.1 Beta or earlier drivers. We hope to have a fix for this one soon, so stay tuned!

Thanks for the info Matt. At least I now know it's not a fault with the hardware. In the meantime I am happy to keep the 15.11.1b drivers installed as Dying Light The Following is the game I am currently playing through.

 

[ICDP]

The developer plays a significant part, though, don't they?

Not in this case, it's a clear problem with the latest Crimson Drivers. I do applaud that AMD are attempting to keep power usage and as a consequence temperature lower with their clock fluctuations but it would be great to have a simple option to turn the option off.

 

[ICDP]

This a bug and not expected behaviour.

OK, thanks.