I just tried
compiling an app using various combinations of distcc settings. My desktop
is a P4 at 3 GHz
make
-j8
43.882u 4.608s
0:41.31 117.3% 0+0k 0+0io 292pf+0w
Add a P4 1.5 and
turn on distcc
35.190u 3.872s
0:30.98 126.0% 0+0k 0+0io 1pf+0w
Add a dual PPro
200
33.142u 3.960s
0:27.47 135.0% 0+0k 0+0io 0pf+0w
Add a single pentium
233
33.518u 3.880s
0:29.49 126.7% 0+0k 0+0io 0pf+0w
Add four more
pentium machines
27.453u 3.940s
0:44.51 70.5% 0+0k 0+0io 0pf+0w
So it seems that
theres a point where too many machines in a distcc chain make it
suboptimal. To test that I set my distcc_hosts to localhost and the five
pentium class machines.
37.002u 4.016s
0:54.17 75.7% 0+0k 0+0io 0pf+0w
In short - distcc
requires your compile farm to be not-too-old. Have I made any wrong
assumptions? Maybe the -j8 should increase as the machine pool
grows?
