make -j$n buildworld : use of -j investigated

[Rob]

Brian Szymanski wrote:
> Did you try any machines that used Hyperthreading? I'd be interested to
> see how those machines fare based on the number of logical and real CPUs.
> 
> 
>>Although people suggest "-j4" as optimal in general
>>case, I have come to a very different conclusion:
>>
>>1) single CPU with enough RAM (2 GHz, 512 MB)
>>    there's no significant speed up in the range
>>    "-j1" to "-j9".
>>    So "-j1" is as good as "-j9".
> 
> 
> If you went to all that trouble, you might as well post the numbers :-)

Time unit is minutes.

CPU: 2x800 MHz    2000 MHz    333 MHz
RAM:  1024 MB      512 MB      64 MB
-j   --------------------------------
1        99          50        276
2        58          49        291
3        58          50        367
4        57          50        547
5        58          49
6        58          50
7        57          50
8        58          50
9        58          50


Rob.