Embedded X

[John Tapsell]

> Are there any performance differences between Xorg and kdrive? Is EXA
> better than KAA?

My tests with the very lastest OMAP boards:

I found a 20% speed improvement on the OMAP between kdrive fbdev KAA
and xorg fbdev EXA.  However I didn't not use the most recent version
of kdrive for the comparision, so I don't know what the difference is
now.

I found no memory usage difference between the newest kdrive and newest Xorg.

> The development effort of writing a new kdrive server (based on Xfbdev)
> vs writing Xorg driver for a new hardware? I guess kdrive is easier and
> cleaner, maybe because I'm not at all familiar with Xorg development.

It is a harder to get started with Xorg because there's quite a bit of
code that you need to get started.

However writing the Xorg driver is much cleaner.  It is a separate
driver, and can be compiled etc completely independently of Xorg.  For
KDrive, however, it's much more 'built-in'.

Also there are things you can do with an Xorg driver that you can't do
with kdrive.  For example manage your own pixmap memory - essential if
you have a UMA system (unified memory).

So basically I would join the chorus here in recommending to go with Xorg

John