On Jul 4,  3:17pm, Wolfgang Solfrank wrote:
> Subject: Re: FPU
> > Hmm, the RS6000 (Rios2?) is similar spec to the PowerPC 620 chip.
>
> Hmm. Not really true.
>
> For one thing there are RS6000 machines with PowerPC 601/603e/604 processors.

Ah, I've only ever used the high end ones, obviously :-)

> Plus the Power and Power2 processors in RS6000 machines are 32-bit
processors,
> just like the 601-604, and not 64-bit like the 620.
>
> And while the Power2 machines have a significant advantage in floating point
> performance over the PowerPC processors (which is probably less so with the
> upcoming 200 MHz 604e), the 620 isn't significantly faster in this area than
> the other PowerPC processors (probably even slower currently due to its
> currently slower clock).

I've benchmarked a few AIX boxen on FP dominated codes (CFD) and the 620 was
faster than Power2. Of course because of the way these chips are designed the
compiler, compilation options and arrangement of code you use are critical -
YMMV.

Cheers

Rob Black

--