Francisco Javier Mesa-Martinez
lefa at ucsc.edu
Tue May 6 03:26:37 CDT 2003
On Tue, 6 May 2003, Bjorn Ramqvist wrote:
> Oh, in that case. I see.
> Now for my curious mind; what's so funky with it? :-)
I think Dave likes the rarity factor associated with the R8K. He has an
exclusive taste, which I admire.... anyone who runs a cray at home has both
my respect and my condolences (for the electric bill that he may get that is).
I like the design, I just like to poke fun at it since I had to code for
it in a previous life. And there is this whole love-hate relationship :-).
What makes it an interesting design, is the fact that it seemed to be
build around the FP unit. I.e. is a FP processor with an integer
co-processor (like the ol' PC used to have an FP processor as an option
:-) ). The machine was the first super-scalar MIPS machine (I think) and
it was quite wide, except that most of the width was allocated for FP
units. The FP units themselves had a lot of ordering constraints on them
in order to get decent performance (i.e. enough vertical independece to
keep the parallel units busy, and enough horizontal ordering to prevent
pipeline hazards too). I think it is a good example on why CPU designers
should first look at code traces! And that one should NEVER EVER put blind
faith on the promises that the compiler guys make.
I have Dave beat when it comes to strange MIPS machines: I actually love the
R6000! Now beat that... it was a POS chip, yet it just registers high in my
geek-meter. I like people who say f CMOS I am going to be a real man, I am
going to do my chip using ECL! (looks at the TERA GaAs module sitting right
next of his monitor and winks). LOL, I can just picture the nightmare of
integrating the R6K chipset and produce a system around it. Damn, ECL, TTL,
and CMOS levels in a single board!!! I bow down to that! I also love for
some reason those products that bring companies to the brink of extintion.
Ehe ECL R6000 almost killed MIPS, and TERA's decision to use GaAs should
have sent red flags to the original investor: Yeah, I have this new
architecture, which requires new compiler technologies and whatnot... and
guess what I am going to implement it using GaAs. That my friends is
called having some seriously large gonades!!! And I respect that!!!
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