Strangely iotop is showing unity-system-compositor's "Mir/Comp" thread is one of the top disk writers. If that's the problem then USC holding on to bypass frames too long would explain it.
** Also affects: unity-system-compositor Importance: Undecided Status: New ** Changed in: unity-system-compositor Importance: Undecided => High ** Changed in: unity-system-compositor Status: New => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1664150 Title: [performance] Unity8 rendering hiccups/stutters exactly every 5 seconds in unison with disk activity To manage notifications about this bug go to: https://bugs.launchpad.net/canonical-devices-system-image/+bug/1664150/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs