A few more points about this. When I first stated looking into this, I found Xorg reporting a few things:
- No access to /dev/fb0 (since I wasn't in the video group) - Acceleration seemed to be disabled However after adding myself to the video group (for access to the FB and DRI devices), and explicitly enabling glamor accel, performance remained terrible after logout/login. After switching back to the intel driver, performance very noticeably improved. The attached Xorg log is using modesetting, after the two tweaks were made above. ** Attachment added: "Xorg log when using mode setting driver" https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1632165/+attachment/4759080/+files/Xorg.0.log.old -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1632165 Title: modesetting driver unbearably slow on MacBookPro12,1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1632165/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp
