[orca-list] Orca performance observations in Firefox

[Jason White <jason jasonjgw net>]

The following may help to illuminate the hitherto undiagnosed performance
problems which some have reported with Orca. These observations are with my
laptop.

Hardware: AMD Athlon64 CPU, 1.8ghz (ondemand CPU frequency governor in effect,
therefore the CPU frequency is down at 800mhz for most, if not all, of the
Orca session).
Baum SuperVario 40 braille display (distributed by Humanware as Brailliant
40).

Software: Debian GNU/Linux, Orca 2.22.1, Gnome-speech 0.4.19, eSpeak 1.37,
, BRLTTY 3.10 (development), Firefox 3 beta 5 as packaged by Debian.

If I load an HTML document in Firefox and press the down arrow key very
rapidly a number of times, then stop, I find that the speech is often several
lines behind what is presented on the braille display.

For this test, I have not increased the speech rate from the default.

It appears there is a delay, but that it is manifest in speech only, given
the above combination of hardware and software.

This doesn't affect me in practice, since my usage patterns don't involve
rapid movement with the cursor keys (I mostly use searching and structural
navigation instead). However, this may help to narrow down the causes of what
others are experiencing.