Bill Waugh wrote:
> 1. speed of Q60/60 in bogomips
> 2. speed of QPC2 v3 on a 1.8 gh celeron based PC in bogomips
I probably would have stayed quiet on the subject (because of the
famous wars), but as you asked for BogoMIPS values I need to write
some lines:
I don't have exact figure for either of the two, but I can tell you
nonetheless that QPC will easily lose this contest (in a devastating
way) because BogoMips has no real life meaning at all (and I don't
mean the usual "benchmarks don't tell you everything", I really mean
it has NO meaning at all). The benchmark basically consist of 1 line:
for (i = loops; i >= 0; i--);
i.e. it does nothing at all except an empty loop. The whole code not
only fits within the on-die cache but probably even in the processor
prefetch-queue. I'm not sure in case of the '60, but it might probably
not even get decoded anymore after the first cycle.
This benchmark had a meaning ten years ago, when processors didn't
have caches, pipelines, superscalar designs and other neat tricks.
Today it's obsolete.
Just to show what this means: the Q40 has a BogoMIPS value of about
27. This means that the 68060/80 has an impressive 600% increase in
speed while only having 100% more clock rate. If you however compare
the Dhrystone (which is far from being perfect, but at least much
better than BogoMIPS) results you get 36443 to 100603, i.e. 276% more,
which is much more realistic (tasks involving hardware like graphics
will BTW usually gain less).
OK, one might ask, "then how do they compete in real life". In that
case I must say this depends on how you define real life. I have no
doubt that the 68060/60 will beat the mentioned QPC/Celeron
combination in pure integer number crunching any time, any place (only
the most recent PCs come within the range of close competition). On
the other hand I'm sure it will lose when there's a lot of QDOS
floating point arithmetic to do (SBASIC programs), in matters of I/O
(WIN, PAR) or certain basic high colour graphics tasks (e.g. draw a
block or move a rectangle, very important for the PE).
> I'm quite aware that benchmarks are not the be all and end all, but
> they are a factor to consider along with others,
Of course. I'd just not rely on BogoMIPS. There's a reason some people
advertise with it ;-) I'd suggest Dhrystone, QSBB (on identical SMSQ/E
versions) and Test909 (the latter two being especially good if the
main use for the machine is SBASIC).
> I used to be indecisive but now I'm not so sure,
Even more confused now? In that case it's the best to get both ;-)
Cheers, Marcel (Confuse-a-cat Inc.)
And now finally off to bed, sun's raising soon ;)
