[FreeNX-kNX] NX screen refresh performance

[--[ UxBoD ]--]

Hello all,

I am looking for a little bit of explanation on how the X11 session is delivered to the client; and whether improving the performance of the local X11 server would improve the overall experience?

I notice a real lag of the screen when I resize images or even move windows around the screen.

As a reference point I ran x11perf while connected to a remote session with the following results:

x11perf -copywinwin10
x11perf - X11 performance program, version 1.2
The X.Org Foundation server version 60900000 on :54.0
from uxbod
Thu Apr 29 15:18:53 2010

Sync time adjustment is 0.0263 msecs.

  36000 reps @   0.1401 msec (  7140.0/sec): Copy 10x10 from window to window
  36000 reps @   0.1460 msec (  6850.0/sec): Copy 10x10 from window to window
  36000 reps @   0.1457 msec (  6860.0/sec): Copy 10x10 from window to window
  36000 reps @   0.1424 msec (  7020.0/sec): Copy 10x10 from window to window
  36000 reps @   0.1450 msec (  6900.0/sec): Copy 10x10 from window to window
 180000 trep @   0.1438 msec (  6950.0/sec): Copy 10x10 from window to window

when I run the same test on my physical laptop which has a NVidia Quadro card I get:

x11perf -copywinwin10
x11perf - X11 performance program, version 1.2
The X.Org Foundation server version 10604000 on :0.0
from cyborg
Thu Apr 29 15:19:18 2010

Sync time adjustment is 0.0979 msecs.

2400000 reps @   0.0020 msec (492000.0/sec): Copy 10x10 from window to window
2400000 reps @   0.0021 msec (486000.0/sec): Copy 10x10 from window to window
2400000 reps @   0.0020 msec (502000.0/sec): Copy 10x10 from window to window
2400000 reps @   0.0020 msec (488000.0/sec): Copy 10x10 from window to window
2400000 reps @   0.0020 msec (496000.0/sec): Copy 10x10 from window to window
12000000 trep @   0.0020 msec (493000.0/sec): Copy 10x10 from window to window

Reading one of the NX documents about slow performance it mentions:

"Upgrading to a more recent version of the X server or trying a different video driver can surely offer a great boost. For example a hardware accelerated video card is recommended to obtain the best speed."

Would that statement refer to a local video card or in the server itself ? as my local machine is already running accelerated.

Would one of the devs be able to cast some light on where I should look to tune the performance?

-- 
Thanks, Phil