Total Commander

TC 9.51 64-bit, Windows 8.1, Windows Server 2019, VM Windows 10 Insider

I was comparing two text files in horizontally split window and used mouse wheel to scroll down.
When bottom was reached, every notch on the wheel was causing redraws - text in both panes jumps about one line up and immediately goes down to the correct position, thus causing quite unpleasant blinking.

For vertical splitter the issue was easily seen in binary comparison mode, and in text mode it could be seen in Virtualbox.
Possibly slower redraws in Virtualbox make the issue more pronounced.

No similar effect was seen when rolling the wheel up at the top.

This sounds pretty much like this topic: https://www.ghisler.ch/board/viewtopic.php?f=16&t=63251

Thank you.
Yes, the same. There are other dual-pane comparison tools without the issue, and strange that here it was "almost impossible to avoid".

Recent editions of Windows 10 might have slightly different path to this setting, but in 8.1 it was:
Control panel - System - Advanced System Settings - Advanced (tab) - Performance/Settings (button) - Adjust for best appearance.
By default, after installation most of the checkboxes in the list below are marked.

When Windows used all these graphics "improvements", it made everything slow - especially, in VirtualBox .
The issue with the mouse wheel was easy to reproduce.
Selecting "Adjust for best performance" speeds up graphics a lot, and the mentioned issue practically vanished.