David Kanter (dkanter@realworldtech.com) on 9/4/06 wrote:
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>
>Niagara II is a fully integrated server on a chip that is a natural extension of
>Niagara I. It is projected to deliver 2x the performance of its predecessor, and
>includes quite a few improvements aside from increasing the throughput. Our article can be found at:
>
>http://www.realworldtech.com/page.cfm?ArticleID=RWT090406012516
>

Excellent article.

BTW, I predicted 8 months ago that Niagara II would have two ALUs per core (and one FPU) and the ability to execute instructions from 2 threads each cycle.

http://realworldtech.com/forums/index.cfm?action=detail&id=60907&threadid=60800&roomid=11

http://realworldtech.com/forums/index.cfm?action=detail&id=60941&threadid=60800&roomid=11

"I'd have to guess that the Niagara2 cores will have some kind of primitive SMT... Niagara2 [could] execute 2 instructions from 2 threads PER CORE... A simple SMT core could always assign instructions from different threads to the two ALUs."

[ASIDE]
In response to my speculation, Paul DeMone politely disagreed, however Jon Anderson hinted that I should stop posting: "No wild theories to explain unsubstantiated data is necessary from anyone... I suggest waiting for more real data..."

But now it turns out that what I speculated about Niagara2 is in fact the case. It's funny that a SUN employee would dismiss correct speculation as "wild" and "unsubstantiated"...
[END ASIDE]

...Anyway, it seems likely that Sun's claims of 2x performance over the first Niagara are reasonable. It appears that Niagara2 will be able to execute a theoretical maximum of 16 instructions (from 16 threads) per clock @ 1.4GHz. Of course, I realize that MIPS (millions of instr per sec, not the SGI CPU) is a silly index of performance, however in this case there's good reason to believe that Niagara2 will achieve results reasonably close to the theoretical maximum much of the time.

...I've been a Niagara booster for awhile, and the more I think about it, the more I become convinced that the "throughput" approach is the best strategy that Sun could have devised.