[Closed]MPO working on one GPU only

[soft slate]

DxDiag reports MPO MaxPlanes: 3 for my Arc A750, but 0 for my RX580. As a result, using WGC drops my monitor's refresh rate to 48hz when the cursor is displayed, which is the lowest refresh rate for my monitor's VRR range. WGC works without issue when not using the secondary GPU.

What I've tried:

• Using one monitor only
• Both DisplayPort and HDMI
• Changing OverlayTestMode in the registry
• Reinstalling both drivers with DDU

Relevant specs:

• Render GPU: Arc A750
• Secondary GPU: RX580 8GB
• Monitor: Gigabyte M27Q

[torn vale]

Im not expert on this but isnt that normal? When you use rx 580, that gpu handles lsfg and it doesnt have mpo. There is a tooltip saying in ls app that wgc wont work properly when you use vrr and hardware cursor is shown. I assume your issue is related to that. Did you try dxgi? It doesnt work either? I think disabling vrr will fix your issue but if it were me, i wouldnt sacrifice vrr for it tbh especially if dxgi capture api works properly

[soft slate]

The WGC part of the tooltip specifies that MPO support is needed for VRR to function with the hardware cursor on screen (I forgot to mention that part, it does this specifically when the cursor is on screen and works fine on the secondary GPU otherwise) and it works fine with my Arc A750 for LS, but breaks VRR when using the RX580 which apparently has MPO disabled. DXGI works mostly okay, but I get slightly higher latency and stutters that seem to come from VRR occasionally not working. I have no idea why DXGI causes VRR to behave inconsistently but this doesn't happen on my A750 or even my RX580 with WGC.

[torn vale]

im not really sure what the real issue with dxgi is but you can try disabling flush setting in ls config. It is in lossless scaling steam app folder (config.ini). Flush 1 is default value (enabled), just make it 0 and test dxgi. That fixed my weird fps drop and stutter issues with lsfg

[soft slate]

Thanks! That actually seemed to help with VRR behaving strangely with DXGI, but only with a queue target of 1 for some reason. It's not ideal, but it'll suffice while I test the GPU in another PC or whatnot to see if its a hardware issue.

[torn vale]

does your secondary gpu have headroom when you enable lsfg?

[soft slate]

GPU-Z reports the maximum usage to be ~85% depending on the game, I think that's a decent amount of headroom

[torn vale]

what base fps you get when it is at 85? And do you go over that base fps? You know secondary will be utilized more if you get higher base fps

[soft slate]

It hits that when I cap the fps to 75, I don't use LS with uncapped fps

[torn vale]

So you dont go any higher base fps i assume

or multiplier (at 75 fps)

[soft slate]

Always 2x unless I'm using it for movies/videos

[torn vale]

i didnt exactly understand what happens when you use queue 0

fps drops? And what max latency value you use?

[soft slate]

Freesync stops working, my monitor will show 165hz in the osd and there's visible screen tearing

max frame latency of 10, I tried messing with it but I don't think it makes a difference

[torn vale]

same with all sync options?

in ls

[soft slate]

I have vsync disabled in LS if that's what you're asking

[torn vale]

tried enabled?

default sync

[soft slate]

Yes, but that's just vsync which does solve screen tearing but not stutters from refresh rate not matching framerate

[torn vale]

with queue 1 variable refresh rate works as intended? Without any issues

[soft slate]

More or less - my monitor OSD will report its refresh rate from anywhere between 90 and 150hz despite LS showing 60/120, but it very much feels like 120hz and I don't notice any issues aside from the extra latency from queue target 1

[torn vale]

are you sure you dont have any overlay btw?

enabled

like discord

[soft slate]

With queue target 0 it sometimes changes the refresh rate but at least half the time the monitor will say 165hz and there will be stutters and tearing

[soft slate]

Nope, I have these disabled and don't usually have anything open when playing games besides LS and firefox

[torn vale]

i dont really know about intel gpus but for example amd has instant replay thing causing issues if i get it right, even when it is not active it cause issues. Idk if you have anything like that or not but there can be something. Also i recommend keeping your driver settings at default values in both amd and intel. Also disable enhanced sync in amd driver if you have it enabled

you have amd driver i assume disable that if you have it enabled or something like that one (instant replay)

I havent noticed before but fps going up to refresh rate seems like an overlay issue to me in general

especially with dxgi there are more interference

wgc doesnt really care about them most of the time (other than discord overlay and instant replay i think)

[soft slate]

The only change I made to intel's software was a custom fan curve, their software is pretty terrible basic, and I turned off recording and notifications in AMD software. I think I'm just going to test whether MPO works on my RX580 in another PC as the sole GPU, and if it doesn't I was considering getting a 5060ti anyways because of how featureless intel's software is (I also really want to use DLDSR). Thank you for the help though, at least I know whatever's happening isn't a simple fix.

[torn vale]

btw i dont know if you know it but dldsr disables mpo

[soft slate]

god damn there really is no winning lmao

[torn vale]

😄

as far as i know two things disable mpo, dual monitors and dldsr

[soft slate]

That's okay I don't think I need supersampling in games that I'll be using frame gen for anyways

[torn vale]

dldsr is pretty demanding so i never use it with recent titles but in old games it is almost free

still useful

[proven bough]

After a quick search it looks like the rx580 doesn't support mpo. Not totally sure though

Also, as alpcan mentioned, the issue might not be related to MPO and is probably the inherent problem WGC has

[soft slate]

Yeah I couldn't exactly find anything conclusive about MPO support, but searching "rx580 mpo" nets a ton of results about people having problems with it, so I figured there wouldn't be issues if it wasn't supported to begin with

[soft slate]

Likely so, but it does work great on my a750 even with the cursor on screen. I still have yet to test the GPU by itself so I can't determine what exactly is at fault