Comment 16 for bug 19711

(In reply to comment #8)
>
> In this case, I know what's causing the activity. It's the 2D drawing engine
> drawing stuff on the screen while you work. As I said, when the DRI is enabled,
> the 2D engines uses the CP to send commands as well (just like 3D). To get
> around that you'd have to implement a way to switch the accel code between CP
> and MMIO dynamically, or implement 3D using MMIO.
>

O.K. then it makes perfectly sense (on a technical level).

However, implementing a way to switch between CP and MMIO acceleration would be
quite nice, as a c3 CPU state gives me about 25% more battery life (20 to 30
min) and the CPU is appr. 5 to 10 degrees Celsius colder.

Any idea, how much performance drop we would see, if the whole accel would
switch to MMIO ? Just a bit like 10% or much more like 50%?

In generell an xorg.conf option would be great saying "Accel" "MMIO" for those
who need the extra battery life and "Accel" "CP" for those that need maximum
graphics speed.

But this is certainly no longer a "real bug", rather a "feature request" now.

Thanks for the explanation and your help!

Best regards,

Michael