30 Dec
2017
30 Dec
'17
6:04 a.m.
On Fri, Dec 29, 2017 at 04:54:25PM -0700, Kevin Bowling wrote:
I trust your judgement and experience WRT the Alpha.
If you're looking for massive performance deltas, what about ECL
designs like the IBM 3090 and Cray designs in the late '80s/ early
'90s? I believe those were not a multiple but a magnitude faster than
contemporaries.
For vector operations, yes. For stuff that you and I care about,
running the OS, serving up data, not so much.
As I recall, the supercomputers were pretty crappy on anything that
wasn't a vector operation. I helped port Unix to a CDC spinoff, the
ETA-10, and it was faster to cross compile stuff on a Sun 3/280 than
compile it natively.
I haven't run on either the 3090 or the Crays but I've got friends who
did (some of whom still work at Cray) and when I was crowing about what
I could do a Sun nobody told me that it was faster on a cray.
If you were doing scalar floating point, especially at the larger
precisions, yeah, the super computers were better. If you were doing
that sort of thing as a vector, so a vector of 128 bit floats, yeah,
I could imagine that could be a lot faster than a Sun.
SGI did a tick/tock where it was floating point focus, then integer focus.
It's possible that one of their floating point designs kept pace with the
super computers, I know that they went to the super computing conference
each year (I did the power wall over NFS at one). But I don't know much
about floating point, never use it in my code :)
--lm