🚀 go-pugleaf

Paul DeMone wrote:
>aa158@valleynet.on.ca wrote:
>>
>> Two current news items at EETimes:
>>
>> "The Playstation 2's CPU, jointly developed by Toshiba
>> and SCE, is an enhanced version of the device described
>> at ISSCC. The device has floating-point performance of
>> 6.2 Gflops..."
>> http://www.eetimes.com/story/OEG19990302S0026
>
>  It would be interesting to know if this peak performance
>  is obtained with IEEE compliant FP or shortcuts
>  acceptable for 3D graphics.

The specs include 10 FMAC units, so that's where
6 of the GFLOPS come from. I'd expect that they're
sticking to IEEE compliance there.

They might be cutting corners on (some of) the
dividers, though. The FPU is probably compliant,
but the vector units are for MPEG/3d use.

>> "Intel said Merced would achieve 3-Gflops extended-
>> precision floating-point performance and 6-Gflops
>> single-precision performance."
>> http://www.eetimes.com/story/OEG19990226S0012
>
>  This figure is interesting if only to suggest a clock rate
>  target of about 750 to 800 MHz.
>
>  Both of these figures are peak performance values
>  which essentially means you cannot achieve higher
>  performance.  For real applications you typically
>  achieve a lot less.  If the Toshiba chip sustains 20%
>  and the Merced sustains 50% of these peak values
>  on real customer applications it will be impressive.

The Toshiba/SCEI chip should be able to do far better
than 20%, at least in the PSX2. The graphics chip that's
going in there is (theoretically) capable of rendering 75m
polys/s, so it's likely that the CPU will be doing a lot of
geometry - pretty much an ideal application for SIMD
FP.

---
Russ