Avoid using a custom theme. Also, you have the option to limit the FPS of the GUI renderer to e.g. 60 fps, which can help a lot. You can do that by going to HUD -> Renderer -> FPS. Same for ClickGUI.
The speed of the RAM is very important because CEF renders to a bitmap which gets uploaded to the GPU from memory. If this process is slowed down by slow RAM, you will experience lag, no matter how fast your GPU is. Therefore, ensure that your computer's RAM sticks are seated in the fast slots (refer to your motherboard manual) and that XMP is enabled.
You might think this wouldn't help, but I can tell you from experience that it makes a huge difference.
A benchmark related to this can be found here: https://github.com/1zun4/gl-bench
Regarding the "Accelerated (BETA)" option: The reason this option is still in beta is because of a bug in the AMD GPU driver that causes the VRAM to fill up completely, which is why it only works for a short time. It does not seem to occur on NVIDIA GPUs.
You can read more about that here: https://github.com/chromiumembedded/cef/issues/3968
skidunion created this issue in chromiumembedded/cef
open
VRAM leak with accelerated OSR on AMD GPUs
#3968
