The “Use Texture Buffer” isn’t a new option, that’s always been there. But Dmitry and @IvanYossi did rework the way textures are uploaded and measurements show that there is quite a big improvement. Plus, I’ve been inking for hours on end on my M1 macbook pro, and I could feel and see the improvement myself.
There is a hidden, because we’re not sure how safe it is, option that you can add to the kritarc file:
useBufferInvalidation=true
When the function is enabled, the buffer is marked as invalidated right after Krita requested its uploading to the GPU texture. It should potentially increase the speed of texture uploading and reduce GPU memory footprint Krita uses.
Then start Krita from Terminal.app and check whether
supportsBufferInvalidation: true
is shown in the output, if so, this function is supported by your GPU.