Comment 25 for bug 288650

Clemens Eisserer (linuxhippy) wrote :

This is not a simple bug, its an architectural change. The intel dirver switched to EXA, which means hw accaleration.

Although the intel driver does *really* bad with readbacks, this is also java's fault.
JDK7 hopefully will include the XRender based backend I am currently working on, which will even bring hw accaleration to java (instead of trying to make software-rendering faster, like my patch does).

Java does quite often fall back to software rendering, where it has to access the image-content with the CPU.
With XAA image contents were in RAM (because XAA offered almost no hw accaleration), and java was able to access the image very fast with the CPU.
Now with EXA images are stored in VRAM on your graphic card, and now the image-content has to be copied between RAM (when java wants to access it) and VRAM (when X11 wants to access it, like for screen-display).

- Clemens