Flicker when Alt Tabbing and Crossfire enabled

[dr.proctor 10]

I was really happy that Arma3 scaled quite well when using crossfire compared to Arma2.

I played the first campaign chapter and then not at all for quite some time.

No issues so far.

I reinstalled windows and when installing steam i saw the second chapter was released.

Because i didnt have a savegame i had to replay the first chapter and had no issues up to the "tipping point" mission.

When i start the game crossfire is not working, i can see on my second monitor that only one gpu is utilized.

To enable crossfire i have to alt+tab. But since the "tipping point" mission alt+tabbing caused the game to flicker.

The "whole game" flickers, its not only PIP. Changing graphics does not reduce flickering but changes frequency.

Even back in the main menu the background graphics flicker.

Disabling crossfire "solves" the flicker issue when alt tabbing but its obviously no real solution to the problem.

Anybody else having this problem?

[wilf55 10]

Same issue here, if you keep alt-tabbing and then going back to the game it fixes itself eventually, might take up to 5-6 goes. Again, not a solution, but a workaround that allows you to keep CF enabled

[Harzach 2518]

No issue here - what GPU/driver?

[dr.proctor 10]

Oh sorry. Should have mentioned my specs...

i5 4670K

12Gb Ram

2x HD6950, latest Driver Cat. 13.12

[Harzach 2518]

Is Vsync disabled?

[dr.proctor 10]

Is Vsync disabled?

Usually yes but i tried turning it on. Did not help.

I also tried the adaptive vsync radeon pro offers. No help.

I tried various in game settings with no succes. Different options in radeon pro didnt help and not using radeon pro doesnt help either.

I didnt play in a while so i did not try to alt tab until its "fixed" Wilf55 suggested.

If that works i am well not happy but its tolerable.

As it seems only few people have this issue i don't really expect a real fix soon.

[Harzach 2518]

I ask because using any vsync whatsoever causes terrible audio stuttering for me, and I was wondering if there was any connection. Just grasping at straws. The 14.1 beta drivers were just released, maybe give them a try?

[wilf55 10]

Confirming that since the last patch the 'Alt-TAB until it works' no longer works. Tried last night for about 5minutes to Alt-TAB back and forth and the flickering kept going.

I also have 2 x 6950s in Crossfire, but have 13.11 drivers - updating those and will see if problem persists.

[wilf55 10]

Okay, so it seems random...

Most of the time after alt-tabbing the screen will flicker, but can be brought back to normal by alt-tabbing multiple times.

Some of the time it will begin to flicker after the initial alt-tab and still wont come back after 2-3 minutes of persistent alt-tabbing.

Anyone have anything on this one ?

[dr.proctor 10]

Anyone have anything on this one ?

Tried it multiple times. Alt-Tabbing does not remove the flicker for me.

Once its there its permanent until i restart the game.

[focher 15]

Just wanted to share that I have 3x6970s in Crossfire and don't have that issue. Not suggesting you don't, but wanted to give another data point.

[Polymath820 11]

Also a side-note contrary what people believe cross-firing in general won't improve game-performance overall. Because what happens when you "crossfire" it links 2 video-cards together. Crossfire like Nvidia's SLI is limited I think "A guess" 1GB/s and when crossfired the PCI-E slot you have either 2.0 or 3.0 is limited to a set of values. your 16X will be connected to another PCI-E slot and come down to 8X (2 SLI / Crossfired) and then 4X (3 SLI / Crossfired) and then 2X (4 SLI / Crossfired) the bandwidth of a crossfire / SLI bridge does not come even remotely close to a PCI slot. so mathematically it is expressed like this when 16X we are talking about the number of "data lanes" in 2way crossfire a PCI-E 2.0 slot will operate at 528MB/s per lane, so that is 528MB/s*8 = 4224MB/s then 3 way is 528MB/s * 4 = 2112MB/s then 4-way 528 * 2 = 1056MB/s almost equal to that of a Crossfire / SLI bridge. which is 1GB/s so the data is transferred between cards but we have another problem All these slots are trying to "talk to the CPU" and if you are using nearly all the bandwidth on the slots.... lets just say to get the "maximum performance" you need to analyse each component's bandwidth, clock speed and latency. etc. but SLI / Crossfire I personally think is best in "non-real-time environments" Where as I said more SLI / Crossfire bigger area for signals to travel. Therefore higher latency higher response time from the CPU to the PCI slots.

This is also an issue in http://www.mcorewire.com/2012/03/02/the-death-of-cpu-scaling-from-one-core-to-many-%E2%80%94-and-why-we%E2%80%99re-still-stuck/

Amadahls law

https://www.princeton.edu/~achaney/tmve/wiki100k/docs/Amdahl_s_law.html

"In any parallelized program, performance is ultimately limited by the amount of serial code (code that can only be executed on one processor)."

Edited March 3, 2014 by Polymath820
Additional Info

[dr.proctor 10]

Also a side-note contrary what people believe cross-firing in general won't improve game-performance overall. Because what happens when you "crossfire" it links 2 video-cards together. Crossfire like Nvidia's SLI is limited I think "A guess" 1GB/s and when crossfired the PCI-E slot you have either 2.0 or 3.0 is limited to a set of values. your 16X will be connected to another PCI-E slot and come down to 8X (2 SLI / Crossfired) and then 4X (3 SLI / Crossfired) and then 2X (4 SLI / Crossfired) the bandwidth of a crossfire / SLI bridge does not come even remotely close to a PCI slot.

While that is true a Gen3 PCIe lane has almost twice of the Bandwith of a Gen2 lane. So bandwith should not impose a bottleneck.

Concerning Arma 3 i know that CF improves performance quite a lot. Not bumping FPS noticably per se but i can run downsampling with highest settings without having less FPS than with a single card, which makes the game look awesome while maintaining 60fps most of the time.

BUT i started having these issues. For me this is "gamebreaking" because single card graphics settings for 60fps mostly are quite low.

[dr.proctor 10]

I solved it.

Well this only lasted for some time. Flicker back now but:

Using only one monitor definitely solves it for me. As soon as i unplug the second monitor it stops to flicker.

I uninstalled the 13.12 Catalyst and installed 11.1 (first official HD6xxx i think) -> no flicker

Then i installed 11.8 preview without uninstalling 11.1 -> no flicker

Then i installed 13.12 without uninstalling the previous ones -> no flicker

Then to 14.2beta withouth uninstalling -> no flicker

I noticed this behaviour some time ago with my HD5870. Installing the latest driver on a fresh windows installation i had some sort of microstuttering even though i only had one graphics card. I knew before reinstalling windows this issue was not present. After a few hours screwing around with different drivers i noticed when i installed the HD5870 release driver and then updated without uninstalling the previous drivers i could use the latest driver without having the stuttering issue.

Because of that experience i just tried the same process and it worked.

My best guess ist that there are some files in older drivers that the newer versions dont include.

Ps. please excuse the double post, i didnt know it editing would mark the thread with a new reply.

Edited March 16, 2014 by Dr.Proctor

[Mofasa 0]

Please remove this post it belongs somewhere else, my issue can not be related, as win 10 was not released at least not officially in 2014.