
Originally Posted by
schmalzler
No, the demonstration just was, that those CPU-intensive tasks made KWINs Compositing perform bad. Everything runs fine without Compositing. I think the problem is, that the iGPU does not have its own memory (your 5450 has its own), and if the cpu pushes quite a lot of data through the memory bus, iGPU will suffer. Managing textures for many windows and of course rendering to pixmap for each cursor blink will probably go slower, hence the "lag". Turning off compositing and everything went fine, remember? Even the animation of yakuake goes fine: With compositing turned on, yakuake uses kwin for the animation, which goes not that smooth, when CPU is under extreme load; without compositing, it has to calculate it on its own - on the CPU! And that goes smooth as if there was no task running! So the "lag" is not a problem of bad CPU-Design, but of GPU not having its own, fast memory.