Flickering graphics caused by launcher version or integrated GPU? [SOLVED]

Performance is massively inferior versus 1.0.50, with jerky motion in all camera views. There is also game instability on certain setups, including avatar flickering at high frame rates. I’ve previously posted about this here: New launcher (1.0.51) causing stutter on Windows systems

Please reconsider the enforced update and/or investigate this issue. As things stand you’re making my experience substantially worse.

To easily replicate and see the difference, fan view someone with the overhead camera (9) and compare how much stutter there is on the new versus old launcher. Smoothness of the game is very poor on the newer versions, irrespective of frame rate and setup (I’m at 95fps on an adaptive sync monitor). To see the flickering, simply disable vsync and use full screen mode.

So I guess this is the first unfixed thing from the April Bugdate.

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At least more people are hopefully going to see and notice the regression now, instead of me just rocking in a corner angrily mumbling to myself about it. :rofl: Pretty obvious to spot if you are used to Zwift on a decent PC and know what smooth looks like.

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mine just updated to the new launcher… will let you know if I notice any issues, supposed to be a rest day for me however…

yes we all need a day off the forum now and again :rofl:


Yeah, I noticed it. I did a short 15 minute ride and could tell there was some stuttering in the graphics, seems most noticeable when the road turns sharply or at intersections and the camera (view 1 in my case) has to quickly sweep around the corner to stay behind my avatar. I ran the log file through zwiftalizer and it is pretty much the same as yesterday’s ride, no drastic differences there.

I probably would have never noticed if you hadn’t pointed it out :joy: :sob:

Sorry! :rofl:

I’ll openly admit I am pretty pedantic with this stuff but I’ve built quite a few Zwift PCs and spent a lot of time trying to get the game as smooth as possible so it jumps out like mad to me and has done ever since the 1.0.51 launcher was released. It’s got to be related to one of the DLL files the respective launchers copy onto your system. That or telemetry.

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Forgot to mention, the newer launchers also introduce rider flickering at high frame rates. Again, this can be easily replicated back to back with vsync off.

Edit: in fact here’s some videos I made a while back. No changes whatsoever between these two installs except the launcher.

1.0.50: old launcher
1.0.51: new launcher


The program won’t even run for me at the moment unless I use the old 1.0.50 launcher :sweat_smile:

Suspect that’s related to the rendering issue as above, given the GPU you’re using.

Thanks for bringing this up. I recall we talked about it previously, and asked our engineers about it.

Here’s what the launcher app does:

  • Downloads game client files
  • Patches game client install
  • Takes login token and passes token via command line to launch the game
  • The launcher does NOT influence the game client in any other way.

Regarding the two vidcaps you attached: where was your avatar at that point? It there is slowdown on a particular section of the map, we’d like to know which specific section of the route you’re on so we can have the rendering engineers see if there’s anyway to optimize performance. Having the video capture is super helpful and appreciated.

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Both videos were on the road leading to the jungle, where you are spawned using the Road to Sky route selection. There’s no slowdown. I’ve seen this flickering in London and other worlds.

I totally agree that the launcher shouldn’t affect the game. But it demonstrably does. Getting the stutter on video is virtually impossible because of the differences in frame rate, output display refresh rate, capture rate, hosting compression, playback rate and refresh rate on the end display. But I assure you it’s there.


Is the launcher left running after the game client has started? If so, guess it could be unintentionally doing something CPU-intensive in the background every now and then to cause this.

Good question, again there’s no reason for it to affect the game so much (and I’ve seen this on various tiers of system) but I will see if I can check this.


Serpentine 8 route selection, recorded just now. Vsync off, forcing max frame rate.

1.0.50: Streamable Video
1.0.52: Streamable Video

How can that be possible if the launcher has no impact on the game? I will now roll back the launcher and that behaviour will go away again.

The launcher does stay running in the background after the Zwift game launches. You can terminate the launcher to see if it makes any difference.

Fun fact since I’m messing about with the frame counter on and vsync off: the HUD has a ~30fps performance penalty when my rig is maxed out.

Thirty. That’s… crazy.

Doesn’t stop the flickering at high frame rates.

Wow, 30fps difference?! And shame, but not a big surprise, that killing the launcher didn’t help. What on earth is making it stutter just because it’s got a different launcher?

In fairness that’s with vsync off and my system maxed out, it doesn’t scale so it’s not as big a difference at more normal frame rates. But still, I didn’t realise how much impact some text and a minimap could have.

And yeah, I don’t understand it either. I’ve tried messing about copying over some of the individual files that I can see change/update when the new launcher is installed but it doesn’t change anything.