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Weird Regular Frame Interval Glitches

Hello, everyone!

There are some weird frame interval glitches on my system. I am not sure if this is a normal situation.

The above figue was generated with timeByFramesEx.py program. The frame interval suddenly becomes bigger and smaller in a regular speed (about 83-90 frames). I have restarted my pc many times and it always happens. I also tried to close nvidia settings like vsync but nothing works.

Does anyone know what might cause this situation? Any suggestion about how to solve this problem?

Thank you.

My System:
System:
Kernel: 5.7.9-1-MANJARO x86_64 bits: 64 compiler: gcc
v: 10.1.0 Desktop: KDE Plasma 5.19.3 Distro: Manjaro Linux
Machine:
Mobo: MSI model: X370 GAMING PLUS (MS-7A33) v: 3.0 serial:
UEFI: American Megatrends v: 5.H0 date: 01/22/2019
CPU:
Topology: 6-Core model: AMD Ryzen 5 1600
Graphics:
Device-1: NVIDIA GP104 [GeForce GTX 1080] vendor: ZOTAC driver: nvidia
v: 430.64 bus ID: 26:00.0
Display: x11 server: X.Org 1.20.8 driver: nvidia
resolution: 1920x1080~60Hz
OpenGL: renderer: GeForce GTX 1080/PCIe/SSE2 v: 4.6.0 NVIDIA 430.64
direct render: Yes
Python Version: 3.6
Psychopy Version: 2020.1.2

Do you have anything happening in your experiment at that frequency (which looks to be about 1.5 seconds)?

No, the code is copied from the timing demos of Psychopy without modification. I tested the same code on my dual-boot Windows10 in the same machine and environment and the phenomenon disappeared. I guess it may relate to some programs running in the Manjaro.

Very interesting. I read The Timing Mega-study and found the experiments were tested on Ubuntu with kernel 5.0. So I downgrade my kernel from 5.7.9 to 4.19 and it works!!!

There are still regular spikes but the frame intervals are much more stable.