[FreeNX-kNX] Extremely poor performance with Youtube/flash

[Terje Andersen]

On Mon, 19 Jan 2009 02:11:42 +1300
Mario Becroft <mb at gem.win.co.nz> wrote:

> I don't know enough to understand this problem much, but it seems to me
> it must be one of the following:
> 
> 1. Nx uses some pixmap format that is very inefficient for the X server
> to process, and thus requires such a large amount of CPU time. It seems
> most unlikely, however, that this could result in the observed degree of
> slowness.
> 
> 2. I don't know enough about the X server architecture to have a clue
> about this, but here is a hypothesis: when nxssh makes a PutImage (or
> whatever) call, it transmits the begining of the call, then gradually
> transmits the image data as it is received and decompressed. The X
> server begins the drawing operation as soon as the request header is
> received, but before there is any image data. Due to its design, the X
> server does not handle any requests from other clients while it is in
> the process of doing this drawing operation, and it busy waits while
> receiving and drawing the image data. This would explain the
> unresponsiveness of other clients, and the high CPU usage, because X's
> busy waiting would slow down the decompression of the image data by
> nxssh.
> 

Also, look at this:

http://www.nomachine.com/fr/view.php?id=FR01D01271

Regards,

Terje