numbers don't lie ...

[Danny Braniss]

> On Wednesday 13 September 2006 08:36, Danny Braniss wrote:
> > 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?
> 
> Maybe the sunfire's CPU is faster, but has to wait on the harddisk. The 
> buildworld 'benchmark' is probably for a large part I/O bound.

nah, i have run the makefile with serveral different disks, ie
	raid0, raid5, FC, iSCSI, SAS,
and the numbers/times don't change (or not significantly).

and in any case, it's the dell that has the fastest disks, but the user time
is the largest.