That may increase the performance, but doesn't explain why GTK apps are so much faster. Thanks, Jarek Sedlacek On Mon, Mar 5, 2012 at 2:20 PM, Victor Silva wrote:

Maybe -C option can help: -C Requests compression of all data (including stdin, stdout, stderr, and data for forwarded X11 and TCP connections). The compression algorithm is the same used by gzip(1), and the “level” can be controlled by the CompressionLevel option for pro‐ tocol version 1. Compression is desirable on modem lines and other slow connections, but will only slow down things on fast networks. The default value can be set on a host-by-host basis in the configuration files; see the Compression option.

2012/3/5 Sergey Manucharian

...

Hi folks,

Regularly I do not use many Qt applications, mostly Skype. I run it over ssh tunnel from another computer within the same local network for long time. After recent system update I noticed it became very slow refreshing its graphics. I checked several Gtk and Qt applications and found that Gtk ones work almost with the "native" speed, while Qt ones with that damn slow redrawing...

I tried ssh with both "ForwardX11" and "ForwardX11Trusted" - there is no difference. I'm using no DE with xmonad WM (tried TWM - no difference either) in x86_64 box.

Any directions/advices/ideas?

Thanks!

-- Cheers, Sergey

On Mon, Mar 5, 2012 at 2:20 PM, Victor Silva wrote:

Maybe -C option can help: -C Requests compression of all data (including stdin, stdout, stderr, and data for forwarded X11 and TCP connections). The compression algorithm is the same used by gzip(1), and the “level” can be controlled by the CompressionLevel option for protocol version 1. Compression is desirable on modem lines and other slow connections, but will only slow down things on fast networks. The default value can be set on a host-by-host basis in the configuration files; see the Compression option.

Excerpts from Lukáš Jirkovský's message from Mon 05-Mar-12 20:33:

On 5 March 2012 20:21, Jarek Sedlacek wrote:

...

That may increase the performance, but doesn't explain why GTK apps are so much faster.

Thanks, Jarek Sedlacek

My guess is that it's because Qt themes use lots of gradients which are probably transferred as a bitmap, while GTK themes doesn't use such fancy stuff much.

The -C option to ssh indeed improves the performance significantly. Also I've played with Qt themes, and even with simplest CDE or Motif it's very slow without compression, it is likely sending bitmaps all the time... -- Cheers, Sergey