Hacker News Reader

Comment by xioxox | Hacker News Reader

Everyone probably already knows this, but enabling compression (-C) makes running remote X programs more usable over slower connections.

View on HN

And while we're at it, if you need remote X, consider Xpra instead of ssh -X - it's way faster, can survive connection drops, and is far more flexible.

I've not heard of that, is it like VNC?

The best metaphor is "tmux for X programs": the X server runs on the same host as the X programs, xpra then "forwards" the windows over a configurable transport (e.g. via SSH) to the client. X was IIRC intended for local networks, so forwarding it over the Internet is sloooow (both by verbose protocol and naive latency handling) - this takes care of both issues.

IIRC it's written in Python, so it runs in most places: https://xpra.org/

Changing the cipher supposedly helps, too. Probably placebo though.

There's no supposedly for me using compression. I just checked - it consistently takes 3x longer to launch an xterm without compression than with compression (15 vs 45s!).

That's obsolete advice: could have helped 10+ years ago...

Not a bad tip, but using gzip compression over the wire seems pretty stone-age. The proper solution is surely to use a modern lossy video-compression algorithm. Is that possible with X?

It's not something I know a lot about. Is this where VNC steps in?

I don't know much about it, but I'm fairly sure that compressing the Xorg data stream with lossy compression is going to mess it up completely and would require a complete overhaul of the protocol to make that work. VNC is indeed the more standard unix thing (insofar as remote GUIs can be considered standard on unix-likes) that applies lossy compression to the pictures being sent over.

x2go and xpra allow some lossy compression algorithms.

> ... using gzip compression over the wire seems pretty stone-age.

Really? Probably half of all web servers on the Internet (using HTTP/1.1) use it.

> The proper solution is surely to use a modern lossy video-compression algorithm.

The X11 protocol doesn't send bitmaps so I'm not certain that a "lossy video-compression algorithm" is gonna have the effect you think it will.

Reply on news.ycombinator.com