I was running 12.04 with the KDE 4.92 backports just fine. I decided to test out the latest Mesa using oibaf graphic drivers PPA which usually contains Mesa from master (9.1). After installing this I got the issue in this bug report. However, at the time I chalked it up to issues in the latest commits to master. I purged those drivers which made KWin work great again (Mesa 8.0.4) and decided to upgrade to 12.10 which brought with it Mesa 9.0 stable and the exact same issues I had with Mesa master.
Looking over the bug report it seems part of the issue stems from MSAA being used with KWin due to a mistake by an algorithm which the GLES version of Kwin does not do. I decided to test this and installed kde- window-manager-gles. Ran "kwin_gles --replace" and performance was massively improved. However I still have the screen corruptions plus the other re-draw errors mentioned about KWIN GLES. Note I can still get some corruptions even with composite suspended as shown in the attached screen of krunner. This is on a Lenovo x230t with a Intel HD4000 gpu from the i7-3520M ** Attachment added: "Krunner-corrupt-line.png" https://bugs.launchpad.net/ubuntu/+source/mesa/+bug/1061073/+attachment/3418442/+files/Krunner-corrupt-line.png -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1061073 Title: Desktop effects are slow and desktop corruption using mesa 9 To manage notifications about this bug go to: https://bugs.launchpad.net/kdebase-workspace/+bug/1061073/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs