Right now, I'm downloading http://cdimage.ubuntu.com/daily-live/current /vivid-desktop-amd64.iso and soon will be posting the apport-collect reports: one during operation above the "vendor-induced custom throttle threshold" and another after it kicks in.
On Friday, I contacted ASUS for a third time and a couple of hours ago they replied via e-mail that the battery was replaced on my second visit to their customer support center, although their tests revealed no defect in the previous battery or any other hardware component. So now I'm 200% sure it's not a hardware fault. Overnight I tested with Windows 7 and Windows 8.1 (with the appropriate drivers and Asus Hybrid Engine software downloaded from the official support website) In Windows 7, everything works all right. In Windows 8.1 the shutdowns follow exactly the same pattern as in Ubuntu: once the battery charge approaches 7000 mW, the CPU is forcibly throttled down to 800 MHz. If there's a combination of Flash Player running and an above- than-average power consumption, a shutdown happens. If the CPU successfully throttles to 800 MHz without shutting down, everything continues to work as expected regardless of further CPU load or overall power consumption. Another important thing I discovered is that the backlight level does not contribute to the probability of shutdown, although all other power- related Windows options do. Windows 8.1 is much more susceptible to the issue than Ubuntu is. Again, much like in Ubuntu, once there was a shutdown, CMOS data becomes compromised and further shutdowns follow in a totally chaotic fashion until I detach the BIOS battery from the motherboard for a few minutes. I spent hours looking through the manuals but wasn't able to discover a kernel boot flag or something that would ward off any attempts by the BIOS to override the current CPU frequency set by the CPU governor. It appears that this custom throttling mechanism is masquerading as the one activated when CPU becomes critically overheated, so both Windows and Ubuntu see no fault and have to comply. Now I understand this is clearly not a fault of Ubuntu, but still cross my fingers for someone who has the knowledge to create a more streamlined, trusted workaround than the one I'm currently using. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1446027 Title: SNA acceleration causes sudden shutdowns and corrupts CMOS data on the the Asus UX21E ultrabook on a wide variety of kernels since at least Ubuntu 14.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1446027/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
