I recently upgraded from Ubuntu 19.10 to 20.04. I experience the following problem. The graphics is slightly delayed every second or so. This can be seen in at least three ways.
- Video playback where the video freezes for a noticeable amount every few seconds.
- When scrolling in a document or a webpage, where the graphics suddenly jumps.
- When writing text like this, the text will also appear in noticeable spurts.
I have a Lenovo Yoga X1 (4th gen) with a 4K screen (3840 x 2160).
These effects where not present while using Ubuntu 19.10.
Might be related to this issue: Choppy Video playback on Ubuntu 20.04
$ lspci -v | grep -i vga -A 12 00:02.0 VGA compatible controller: Intel Corporation UHD Graphics 620 (Whiskey Lake) (rev 02) (prog-if 00 [VGA controller]) Subsystem: Lenovo UHD Graphics 620 (Whiskey Lake) Flags: bus master, fast devsel, latency 0, IRQ 150 Memory at e9000000 (64-bit, non-prefetchable) [size=16M] Memory at c0000000 (64-bit, prefetchable) [size=256M] I/O ports at 2000 [size=64] Expansion ROM at 000c0000 [virtual] [disabled] [size=128K] Capabilities: <access denied> Kernel driver in use: i915 Kernel modules: i915 00:04.0 Signal processing controller: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem (rev 0c) Subsystem: Lenovo Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem