X viewer speed

Cedric Maion Cedric.Maion "at" insa-lyon.fr
Sat, 07 Mar 1998 17:29:58 +0000

On Sat, Mar 07, 1998 at 04:16:55PM -0000, Quentin Stafford-Fraser wrote:
> Hi Cedric,

Hi !

> I'm a little surprised.  On the same machine under the same conditions I
> would have expected the X viewer to be a little faster, because it writes
> straight to the screen where the Windows one writes into a memory bitmap
> which it blits onto the screen.  But there are too many other factors here
> to do a real comparison.  As you say, the video drivers are different, and X
> generally has more layers between the application and the screen, the
> network drivers and memory usage will be different, and I'm assuming your
> screen has the same resolution, number of colours and pixel format in each
> case?

Yes indeed.
Viewer specs: PII 300, 64MB SDRAM, ATI XPert AGP 8MB at 1024x768x24
Server specs: P100, 32MB EDO (under Red Hat Linux 5)
Network: quite eavily loaded 10Mb ethernet LAN

> There's probably more room to speed up the Windows viewer than the X one,
> but there may be more room for speeding up your Linux environment?

In fact, I've just found that when I use the '-bgr233' option, the viewer
performs _a lot_ better. I didn't take the time to do some benchmarks between
the win32 and X viewer (with -bgr233), but I think it should now be
comparable (I hate leaving my sweet Linux desktop for Windows ;-)
Perhaps you should document the -bgr233 option :)

Anyway, vnc is really great. Thank you for your job.



PS: I asked a friend under Windows to run the vnc server on his computer,
and I used the X viewer to connect to it. There was some (acceptable)
visual glitches, but the most annoying thing was the non working right
shift (it produces circumflex accents). I don't know if it's caused by the
server or the viewer (since I do not have access to the win32 server to 
play with the parameters)... no problem with the X server.
Cedric Maion <Cedric.Maion "at" insa-lyon.fr>