XO battery/performance

Jon Nettleton jon.nettleton at gmail.com
Mon May 28 03:45:17 EDT 2012

http://lists.laptop.org/pipermail/devel/2012-May/035198.html ) I also
tried to test the XO-1(os880), XO-1.5(os883) and -1.75(os10) battery
life and thought to report it. It might be of help to someone.

os10 is very much a development release and not great for testing.  In
particular graphics acceleration was not working properly, so this
test is strictly testing the cpu.


> I can appreciate that this is far from a CPU/computer performance test but taking counts just as an *indication* of CPU/FPU performance would imply that the XO-1.75 is 65% faster than the XO-1 but 40% slower(?) than the XO-1.5.

see above reasoning as to why this is an incorrect assumption.
Although the XO 1.75 will be slightly slower than an XO 1.5 in this
test as it is primarily doing glyph compositing in the terminal.  The
XO 1.5 hardware supports compositing the A8 format via the 3d engine,
while the XO 1.75 only supports rgb565 and argb8888 in hardware so a
lot of the compositing functions will fall back to software.  We are
helping to speed up this fallback by enabling iwmmxt optimizations in

> Considering counts/discharge however, the XO-1.75 appears 33% more efficient than the XO-1.5 and 320%(!) more efficient than the XO-1
> One thing I noticed is that while on the XO-1 and XO-1.5 the output was a constant stream of new lines without and "hesitations" and the cursor barely visible, on the XO-1.75 were "hesitations" and the cursor was appearing at the end of the line during these "hiccups".

These hiccups are probably due to the lack  of hardware acceleration.
However because  the SOC does do more rendering I have also been
experimenting with increasing the buffer for libxcb to help prevent
hiccups between the Xclients and Xserver.

OS12 should be a better image to test on the XO 1.75.


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