On 06/28/2014 09:16 AM, Chris Angelico wrote: >> I remember approx. 10 years ago a neighboring dept. at my work effectively >> killed our 10 MB/s Ethernet segment with such traffic (due to a >> misconfigured switch/router?). Running an ethernet analyzer showed a single >> X11 host-server session occupied ~80% bandwidth. AFAICR, it was a Sun >> workstation. >> A real PITA. > > Either that was a horribly inefficient X11 connection (as mine was - > the virtual machine sent basically a constantly-updated bitmapped > image to rdesktop, which then couldn't do anything more efficient than > feed that image to the X server), or something was horribly > misconfigured. I've frequently done much more reasonable X11 > forwarding, with high success and low traffic;
Only the most primitive X11 apps are at all fast over network forwarding. If the app uses any modern toolkit, then it's basically just sending a bunch of bitmaps over the wire (changes), which would be fine, but X11 involves a lot of server round trips. Forwarding works fine over SSH on a LAN (compression with -X helps too), but anything slower than that is very nearly unusable. I used to run XEmacs over a modem (I know; I just preferred it to Emacs and I didn't know ViM), and it worked great with server-side drawing and fonts, as X11 was designed to do 90s-style. But now if I need to run X11 apps over a slower link these days I use OpenNX which dramatically helps by eliminating round trips, and applying bitmap compression. But the fact remains X11 kind of sucks these days, and "network transparency" now basically means a slightly suckier version of VNC in effect. RDP protocol is actually much more efficient than X11 forwarding with modern apps. So your rdesktop example is actually not a horribly inefficient X11 connection, other than the fact that X11 is inefficient. Honestly once Wayland has per-app RDP built into it, there'll be no reason at all to cheer for X11. -- https://mail.python.org/mailman/listinfo/python-list
