Bug#954845: poor performance for -g 256x50

[Harald Dunkel <harri@afaics.de>]

You can reproduce the performance fall-off by using a slow network connection,
e.g. via IPsec and DSL and public Internet to a remote site. The "small numbers"
case was taken using a local network connection from one Linux PC to another.
Ping shows a round-trip time of 0.3ms for this local connection.

Here is the same sample session as above, now using the IPsec connection
between my office and my home PC (ping: 20ms):

253x50:
real    0m0.037s
user    0m0.000s
sys     0m0.011s


254x50:
real    0m0.032s
user    0m0.000s
sys     0m0.009s


255x50:
real    0m0.032s
user    0m0.004s
sys     0m0.007s


256x50:
real    0m27.316s
user    0m0.018s
sys     0m0.000s


257x50:
real    0m28.837s
user    0m0.008s
sys     0m0.012s


258x50:
real    0m29.157s
user    0m0.000s
sys     0m0.017s


If I use an xfce4-terminal instead of xterm, then the numbers for 253x50 and 258x50
and in between are the same as for xterm with 255x50. Same network connection, of
course. xfce4-terminal does not show the performance fall-off as xterm.


Regards
Harri