Danny Braniss <[EMAIL PROTECTED]> writes: > Im testing these 2 boxes, Sun X4100 and Dell-2950, and: > > SUN X4100: Dual Core AMD Opteron(tm) Processor 280 (2393.19-MHz > K8-class CPU) > one 70g sata disk > DELL 2950: Intel(R) Xeon(TM) CPU 3.20GHz (3192.98-MHz K8-class CPU) > 4 sata disks + raid0 > > they both run identical 6.1-STABLE. > > my 'cpu benchmark' shows the amd being much better than the intel. > but, doing a make buildworld give interesting results: > > dell-2950 : make -j16 TARGET_ARCH=amd64 buildworld : 24m17.41s real 1h3m3.26s > user 17m15.07s sys > dell-2950 : make -j8 TARGET_ARCH=amd64 buildworld : 24m8.28s real 1h2m59.38s > user 16m16.20s sys > > sunfire : make -j16 TARGET_ARCH=amd64 buildworld : 24m21.38s real 49m6.68s > user 14m22.64s sys > sunfire : make -j8 TARGET_ARCH=amd64 buildworld : 23m47.69s real 48m53.58s > user 13m44.81s sys > > which probably says something about my 'cpu benchmark' :-( > but why is the user time so much different between the boxes?
I don't see what's so surprising. User time reflects time actually spent compiling stuff; you can see there that the Opteron is much faster than the Xeon. Sys time is time spent executing kernel code on behalf of the build, which is mostly time spent processing I/O requests (but does not include time spent actually reading from or writing to disks). The reason why there is no significant difference in wall time between the two is that buildworld is mostly bound by I/O and memory bandwidth, not by CPU power. If you have enough memory, place /usr/src and /usr/obj on malloc()-backed RAM disks and see if it makes any difference. DES -- Dag-Erling Smørgrav - [EMAIL PROTECTED] _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
