Xeon 5650 from 2010, rx570 8gb, no stutters or slow fps, but I'm on Linux and not PC so cannot comment.
vivaldi and brave are both chromium based.
Firefox on a 2012-era i7, no problems with video on Linux or Windows.
I built my rig last February with an i3 and an RTX3060. Is that an issue?
I'd guess the graphics driver isn't installed. Sounds like CPU with frame buffer vs GPU acceleration. Do you need to set a browser option to enable GPU acceleration?
Not a lot to go on here.
I turned off "hardware acceleration" on Brave and it fixed it. Weird. I don't remember turning that on, I thought my CPU was the bottleneck, and I always had my GPU driver installed anyway. Thanks man.
I've got i5 and i3 machines from that era and they can do 1080p YouTube just fine. I don't use a video card, just built-in graphics.
(post is archived)