Periodic 10 minutes GPU overload in 4K around every 40 minutes

Bugs and Support
1

Hi there,

I’m using Zwift on two configurations, 9900k + RTX 4060 Ti, and 265K + RTX 5070 Ti, and have experienced very bad freezes of all computer (from 5 to 30 seconds), without explaination.

I’m using a windowed display, Zwift resolution on 4K, on my TV (Sony 4K / 60 Hz), in order to have something else (browsing, video, netFlix, whatever) in another corner of the screen.

To get what’s going on, I’ve run task manager on a third corner of the screen. So here what’s happening while Zwifting :

  • GPU is cruising at 25% load…
  • …and around the 40 minutes mark, the GPU load increases to full
  • To avoid freezing, I’m downgrading Zwift parameters to 1080p, GPU load decreases to around 45%
  • This “overload period” lasts around 10 minutes, then GPU load decreases to well under 20%, allowing me to bring back 4K in Zwift parameters…for the next 40-ish minutes

I’ve done a 2h40 (metric) fondo this morning, so the scheme happened exactly three times.

Nothing special on Zwift (crowding, textures, power on Home Trainer - TacX Neo2T, etc…), CPU is cruising, RAM as well (~ 12 gb used for respectively 32 and 48 gb installed), VRam peaks at 6.6 gb, absolutely clean install (Windows 11 25H2…but was the same on 24H2, DDU before each NVidia driver update), obviously latest NVidia drivers, no network (ethernet) issues (I tested it during each 10 minutes overload periods), I’ve tried to kill my other tasks during the 10 minutes overload period, without any impact on GPU load, and I didn’t touch any of the parameters in NVidia control panel, which are applying VSync on default (no problem to me as my TV is 60 Hz)…so it’s not the GPU going crazy producing lots of FPS. And finally, nothing special on log through Zwiftalizer, looking at a “frozen” log or at a “keep it 1080p for 10 minutes” log.

Hey, Zwift, what’s going on ? :face_with_raised_eyebrow::grin:

Thanks !

2

Do you have OpenGL (which Zwift uses) Vsync and triple buffering active?

3

In Nvidia Control panel, I have :

  • “OpenGL GDI Compatibility” set to “using global parameter (auto)”
  • “Vulkan/OpenGL display presentation” set to “using global parameter (auto)”
  • “OpenGL Graphic rendering processor” set to “using global parameter (autoselection)”
  • “VSync” set to “using global parameter (using 3D app parameter)”
  • “Triple Buffering" set to “using global parameter (off)”

Nothing else with the keywords you mentioned. VSync is active by default, considering Zwitalizer shows steady 60 fps on log files.

4

It’s recommended to enable Triple Buffering and Threaded Optimization, and disable the Zwift Video Screenshots setting if it’s available and turned on. I do not know if any of those things are related to the problem you reported.

5

Thanks for the insight, I’ll try it :slightly_smiling_face:

6

Unfortunately it didn’t work. I’ve tried all the combinations on those 3 parameters, GPU load behaviour still the same, jumping for no reason from 25% to 100%. Depending on the combinations, timing was a bit different though (20 minutes, 30 minutes), but still. Threaded Optimization did generate very strange behaviour, Complete display turning into a 0.5 FPS slideshow, except for the mouse pointer :thinking:

7

If you don’t get any more useful suggestions here, head over to the ZPCMR group on Facebook. Generate a log report on trainerdx.com, hit the share button, and post it there. If you’re not already a member, make sure to go to the Files tab in the group and read the files before posting, especially the Nvidia and monitor guides. Failure to read the files may result in an unpleasant reception.

8

If it is happening on both systems, I would look at some weird setting in the TV or on your home network. No reason why either of those GPUs should be freezing. If you are using nVidia drivers, try uninstalling and only using what Windows provides.
Edit: are you using a common AV? Try disabling…

Note: I use the nVidia drivers for my 4060 because it is a lot easier to show the FPS vs changing the config file everytime Zwift updates and I have no issues like yours.

9

@Paul Thanks, will try that. I assume I’ve a long way of troubleshooting ahead before posting anything on this group :sweat_smile:

@chris nothing special on my home network, as I’ve said I checked it during the overload period, and nothing strange on network load. I didn’t try Windows provided drivers, but from what I’ve seen on every new Windows installation, there are only some older release of nVidia drivers. No common AV neither.

BTW the behaviour is also present on Zwift “ride selection” title screen. When launching Zwift, GPU load over 90% for around 20 minutes on this screen, then drops to 20-25%, and back again to over 90% after some time, and repeat…

10

It’s “normal” to have crazy high FPS on the home screen. But you mentioned having a 60Hz display which I would imagine your GPU can handle easily. Capping the frame rate in Nvidia settings is what you would need to do to reduce load on the home screen. Relatively high GPU utilization is not a bad thing but if you’re getting super low frame rates in game that is definitely a problem. Would be interesting to see your log analysis from trainerdx.

11

Forgot one other thing - your CPU is good enough that Zwift should have enabled the Video Screenshots feature by default. Turn it off if you haven’t done so already.

12

The log of the session I’m talking about in the first post : public/1723370a-cefd-4ed5-bf98-97ee58f366de

1 Like
13

That looks like solid performance to me. The game froze at some point? There’s no sign of any problem with frame rates.

14

I switched to 1080p at some points (around every 40 minutes) seeing GPU load rising to a steady 97-98%. Load then decreases around 45%.

First time I checked with task manager, PC freezes without this preventive measure.

Just done a fondo, with triple buffering on, VSync on, FPS limit at 60, Threaded Optimization on, auto video capture off, same s*** :flushed_face:

Edit : public/77d138ef-0b72-4a39-8a19-55bc0eee9c3e

Finished the session on 1080p, that was those kind of “10 minutes overload” period

15

PC freezes, or game freezes? You had to reboot the machine?

16

Do you have another monitor/tv you can try? to eliminate the Sony? I consider Sony to be one of those companies that thinks they are smarter than you (Apple/Microsoft/etc)…cynical, I know.

Other try is to uninstall the nVidia card(s) completely, delete drivers and directories and reinstall. Long shot if happening on both systems.

17

@Paul third line of my FP, complete PC freeze from 5 to 30 seconds. It comes back to normal after that…and GPU load also comes back to normal.

@chris “absolutely clean install (Windows 11 25H2…but was the same on 24H2, DDU before each NVidia driver update)”

:wink:

My Sony TV is an old one (2017), and I can’t get through which wizardry it could freeze the PC crawling up the HDMi cable. I can investigate that, but not easy on my setup.

BTW, I didn’t have any problem with this TV and an older config (3770K + GTX 1060), but Zwift was obviously running @ 1080p.

18

Borrowed a third GPU, RTX 3060Ti…and it’s even weirder. The issue seems to come from NetFlix windowed + Zwift 4k windowed. GPU load is pretty ok…but NetFlix is unable to display a proper image (stuttering / pixel mess every other frame), and it always ends up with crash : instant shut down of Zwift window, or complete screen freeze, then the system comes back within 20-30 seconds, without Zwift :zany_face:

No issues at all when running Zwift in 1080p. Tell me this way of using Zwift (4k windowed + NetFlix windowed) doesn’t need an RTX 5090, huh ?