I do not know if this helps, but immediately after IDLE (screen off): top with separated CPU-s:
top - 14:38:27 up 6:39, 3 users, load average: 0,70, 0,32, 0,21 Tasks: 200 total, 1 running, 199 sleeping, 0 stopped, 0 zombie %Cpu0 : 0,7 us, 1,0 sy, 0,0 ni, 98,3 id, 0,0 wa, 0,0 hi, 0,0 si, 0,0 st %Cpu1 : 0,0 us, 0,7 sy, 0,0 ni, 98,7 id, 0,3 wa, 0,0 hi, 0,3 si, 0,0 st %Cpu2 : 1,0 us, 0,0 sy, 0,0 ni, 99,0 id, 0,0 wa, 0,0 hi, 0,0 si, 0,0 st %Cpu3 : 34,9 us, 65,1 sy, 0,0 ni, 0,0 id, 0,0 wa, 0,0 hi, 0,0 si, 0,0 st KiB Mem: 8211348 total, 3645980 used, 4565368 free, 108936 buffers KiB Swap: 7844308 total, 0 used, 7844308 free. 2569852 cached Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1396 mark 20 0 288756 114788 70772 S 100,8 1,4 120:45.68 compiz 1800 mark 20 0 866636 332252 78480 S 0,3 4,0 13:16.19 firefox 4454 mark 20 0 125108 34428 26224 S 0,3 0,4 0:13.64 gnome-terminal- 5850 root 20 0 0 0 0 S 0,3 0,0 0:04.45 kworker/0:2 6878 mark 20 0 7172 2832 2364 R 0,3 0,0 0:00.23 top 1 root 20 0 24884 4848 3716 S 0,0 0,1 0:01.49 systemd 2 root 20 0 0 0 0 S 0,0 0,0 0:00.00 kthreadd 3 root 20 0 0 0 0 S 0,0 0,0 0:00.70 ksoftirqd/0 5 root 0 -20 0 0 0 S 0,0 0,0 0:00.00 kworker/0:0H 7 root 20 0 0 0 0 S 0,0 0,0 0:08.01 rcu_sched 8 root 20 0 0 0 0 S 0,0 0,0 0:00.00 rcu_bh So compiz is occupying one of my core 100% only DURING IDLE (screen off) Mark ** Summary changed: - compiz HIGH CPU usage only during AFK + compiz HIGH CPU usage only during screen is off -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1511727 Title: compiz HIGH CPU usage only during screen is off To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/compiz/+bug/1511727/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs