I work with a dual monitor setup, one 4k and one fullHD and don't see any lag in either.
Can you monitor your graphics card and see if it isn't throttling? Does frame drops happen in games or other 3d apps?

In T71034#800147, @Daniel Santana (dgsantana) wrote:

I work with a dual monitor setup, one 4k and one fullHD and don't see any lag in either.
Can you monitor your graphics card and see if it isn't throttling? Does frame drops happen in games or other 3d apps?

I can see the usage and clocks spiking when I do something in blender, but it never goes past 60% of usage. I just noticed this in Blender 2.80. Zbrush and Blender 2.79 are both smooth.

I tried with an old 2.80 version (End of November of 2018) that I had archived and the problem is present also. I noticed this problem yesterday, so I doubt I had it before because I've been using blender for more than a year now and I'm pretty sensitive to those kind of problems.

I made this video, I hope you can see the problem. It's the frameskipping that happens right when I start rotating the camera. It doesn't look so bad on video, but it adds up when modeling and it gets pratically impossible to model.

ZBrush is more CPU bound, their viewport engine doesn't require some beefy card. I asked that because on another workstation I have which has a Radeon Pro card, it has hiccups but it's due to bad drivers which cause the GPU to overheat and then it starts to throttle, causing frame drops, on 3dsmax, Maya, sometimes in Blender.
I tested 2.80 on Radeon Pro (FullHD), Geforce GTX 2080 Super (4k, FullHD), Geforce GTX 1070 (4k, , FullHD), Geforce GTX 1060 (dual 4k), Geforce GTX 870M (FullHD), and didn't see hiccups on the viewport, this in both Windows 10 Pro, and Ubuntu 18.04.

I don't have any other programs but ZBrush and Blender in my PC, but I'll install the trials to try.

The frame drops happens right on the start of the movement, if I keep moving the camera it gets normal, it's like the GPU is taking a while to wake up, causing a couple of frames to drop.

I noticed that the spikes in clock and usage are the same in blender 2.79 and 2.80, but 2.79 runs smooth.

Also, if I turn on the rendered viewport with cycles, it runs normal, I believe it's because the GPU is running constantly in this case.

It's weird because this problem started so out of nowhere. I had to left my PC off during 2 weeks because I was moving but now that I have to get work done, I can't :(

My PC at work has a 980Ti and 3 1080p monitors and it's so smooth there. My colleague uses a 4k monitor with a 1080p on the side and it also runs smooth on his computer (also a 980Ti).

I guess I'll have to format my PC on the weekend and hope this fixes the problem.

Maybe trying a newer driver version, even if a beta one. I had quite a few problems due to bad drivers, and with 2080, it was a party in both Windows and Linux (in the bad sense).

Can you tell me what driver version are you using? I had 417.something that was probably a year old and then I installed the newest one, uninstalling the old one with DDU and it didn't work.

I'm using 436.48.

And I had lots of issues with the Workstation driver, CUDA and Optrix simply didn't work at all, so I had to switch to the game ready drivers.

I'll try this one. I'm currently using 440.97.

I asked my friend to use his PC and to my surprise, the problem also occurs here, but he haven't noticed until I said it to him.

I'm a little bit relieved because it isn't a problem with my GPU, but still frustrated.

Do you know if there's a way to force the GPU to always run in Blender? Like 5% or something and boosting when needed.

In T71034#849970, @Richard Antalik (ISS) wrote:

Is this still an issue with latest build? https://builder.blender.org/download/

I'll test when I get home.

I managed a "solution" that is to leave something that uses GPU running on the background, like some video. Later I found out that setting the power mode on nvidia panel to "Prefer Maximum Performance" solves completely the issue.

As soon as I can test the new build, I'll update you.