Question / Help Thread/core issues with Ryzen 1800x

[LeNwAr]

Hi, I've just upgraded to a new Ryzen 1800x system, specifically with recording and streaming in mind. I've had some issues with Overloaded Encoder errors, regardless of what bitrate or quality settings I was choosing, until I came across the problem. It may be an issue with Ryzen, maybe Windows, maybe OBS, I have no idea, so this might be a little long-winded, but I want to include all my troubleshooting steps in an attempt to provide some usable information, or to help others having the same experience.

All of this was tested recording Battlefield 1 on Win 10 pro 64bit, with an 1800x clocked to 3.8ghz on all cores and 16gb of 3200mhz ram. I haven't had a chance to test this with other games yet, but I assume the results would be similar. Also here is my log from this current session I took the screenshots from:
https://obsproject.com/logs/NWtzzd4Kq1oP7jum

When I first started having issues, changing encoder settings made very little difference. After playing with these for a while, I decided to look into other possibilities. I checked my CPU usage after starting to record, and I noticed that only 4 threads were being used by OBS for encoding. Here is my CPU usage from before and after starting to record. You can clearly see the 4 threads which are being used.


After noticing this, I decided to have a play round with CPU affinity to see if I could manually set cores. So I set BF1 to my first 8 threads, and OBS to my last 8 threads. As you can see, this evens out the CPU usage and causes OBS to use the last 8 threads pretty evenly.


This issue now is, when I change Windows' focus back to BF1, OBS stops using all but one thread, and I'm sure you can guess what happens to my recordings. Once I focus back on other programs on my desktop, the CPU usage evens out to the 8 threads again.


Now when I go back to affinity settings and untick the thread which is being maxed out (number 10 in this case), OBS is then able to go back to using the remaining 7 threads for encoding, and I can even select additional threads for it to use with no further issues, as long as that offending thread is left unticked. It's not the same thread every time either...next time I start OBS it may be a different thread, but the results are the same and repeatable.


So there is an issue here regarding thread utilization. This could be caused by a number of things, but I wanted to put this information up in the hopes that it helps someone, or may help the OBS team find an issue somewhere. If anyone would like some more details or wants me to test anything else, let me know.

Thanks.

 

[BK-Morpheus]

Is this a fresh Win10 Install including AMD Chipset drivers?
My 1700x is behaving fine, when it comes to OBS and CPU thread utilization.

 

[LeNwAr]

It is quite new, only installed a couple of weeks ago, and yes I've installed all motherboard and AMD chipset drivers as well. Might be worth reinstalling them though to see if that makes any difference, thanks.

 

[LeNwAr]

Alright for a quick update, I have done a fresh Windows install from scratch, and my thread issues seem to have been resolved. Being a fairly new install already, I hadn't really considered it to be a driver issue, but it seems something was messed up somewhere.

 

[LeNwAr]

So for a final update, I found the source of the problem. Turning Windows Game Mode on causes Windows to decided that OBS is only allowed 4 cores. So there was likely nothing wrong with my computer before, it's just that I had Game Mode enabled, and never thought to switch it off.

 

[BK-Morpheus]

Thanks, good to know, but on updated Win10 branches, you can't turn Game Mode on. In older Win10 versions, there was an option to turn it on or foff, but that option is gone in newer versions and windows ist just showing, that this PC is supporting Game Mode.
Game Bar and Game DVR on the other hand can be disabled (and I would recommend to do so).

 

[koala]

In current Windows 10 branches, Game Mode is off as default, and you cannot activate it globally. You can activate it only per game by starting the game, then activating the game bar, then activating Game Mode from the game bar. If you don't do this, Game Mode stays deactivated for this game. However, there may be games that activate Game Mode by themselves, at least this is what is written in the Windows Game Mode help page. In this case, you probably can turn it off via the game bar.

Interesting side note: if you go to the Windows "Game Mode" settings page where you get the information that Game Mode is supported by the PC, you have a link to "Graphics Settings" on the right column of that page. If you follow that link, you get the option to add app-specific configuration to run that app on a certain GPU, if you have multiple GPUs. In the past, you were able to do this in the Graphics driver settings of laptops only, but now you can do this on desktops as well. If you move an app or OBS itself to the "wrong" GPU, you can reproduce the black screen problems on a desktop people are having with laptops.