Strange Nvidia Driver behaviour/iGPU behaviour

CJH123 · June 9, 2020

Ok some I'm going to cut to the chase because that title must have you thinking what!?

Anyhow I'm running a 980 ti with the latest drivers. I recently have got more into watching HEVC and VP9 content, the 980 ti dosent have full hardware decode support. But my system has a 7700k with an iGPU that can hardware decode HEVC and VP9! So problem solved right! Use iGPU for video decode and the 980ti for everything else. Well I thought that but I have come across two stange behaviours and I'm wondering if people have answers or fixes.

First off I'm going to state this. My 980ti is still set to be the primary display adapter, this way I only have to tell programs to use the iGPU in Windows Settings, since easier since all I can do is set Chrome, VLC and any other software I'm gonna be watching videos in boom done.

Scenario 1: Both monitors connected to 980 ti, HD 630 enabled, Chrome, VLC set to use HD 630. Video Hardware decoding flawless, but when browsing some webpages and sites like Facebook, it can stutter, if stop scrolling do nothing then resume their is delay and I gets annoying quickly, things like replying to messages become slow to respond to my input . I chalked this up to the iGPU essentially having nothing to do when not doing any load this is what causes the delay to occur.

This is the first side of the issue, I came up with a fix for that issue but that's where it gets more interesting to me and where I think the fix could be found.

Scenario 2: Primary Monitor is driven by 980 ti, Second monitor by the HD 630, Chrome and VLC still set to use HD 630. Behold I was right, now the iGPU is driving a display it no longer lags in Facebook or when scrolling it's butter smooth. VLC plays fine and uses the 630 to decode HEVC. However the moment I try to play a Video in YouTube, Chrome freezes and the Nvidia driver crashes out. After it crashes many times it will block Chrome from accessing the 980 ti at which point the setup works as intended until that instance of Chrome is closed. If both displays are connected to the 980 ti and one is switched to the iGPU during playback, no issues occur. Even attempting to use Edge the same behaviour occurs. However again on Facebook Video plays fine and Task Manger shows that the HD 630 is hardware decoding the video, no crashes occur in any browser or video driver.

I'm basically at a loss. For now I just went back to the 980 ti, iGPU disabled. I know it's not the perfect setup, but the 980 ti is still amazing and I have this iGPU sitting here that has the hardware decoders the 980 to lacks. Why won't it play ball? I'm sure I figured the first example out but unless I'm constantly forcing a load on the iGPU it causes that massive delay and then to fix that, giving it a display to drive I end up with the issue of YouTube crashing out the Nvidia driver constantly....

Really I wanna know what's the fault... Is it the Nvidia driver? Chrome? YouTube itself? All three of those work fine for viewing video on Facebook with the HD 630 as the gpu render for Chrome. Also I know I could try it the other way. But I don't want to spend forever adding every game and graphics intensive resource in a list. I only basically want programs that can make use of the HD 630s better hardware decoding to utilize it that's what both these uses cases do. They don't even touch the iGPU unless it's for a program I want to have the extra decode support in, which is basically just Chrome, VLC, Kodi etc

Any advice would be appreciated. Maybe this is something I should talk to Google and Nvidia about? A bug maybe. Just stange how it only happens with YouTube.