[rescue] SGI, Origin 200, and speed?

[James Braid]

Charles Shannon Hendrix said the following on 1/05/2004 3:00 a.m.:
> Thu, 29 Apr 2004 @ 18:22 -0400, Dave McGuire said:
>>>I figured if they did that, they might make it available for older
>>>machines, and that you might know about it.
>>
>>  I've not heard of any such thing, but then I'm not up to speed on 
>>their absolute newest stuff.
> 
> 
> The Origin 3000 website talks about Xtown2 ports as being bidirectional
> 1.6GB/sec interfaces, which is faster than Craylink.  It seems to be
> used for I/O though... in fact I'm reading the site now and don't see
> where it specifically says what is used for the interconnect fabric.

CrayLinks name got changed to NUMAlink after SGI got rid of Cray.

The Origin 3000 uses NUMAlink3 which is pretty much the original 
NUMAlink running at a higher clock rate and gives you 1.6GB/sec 
bidirectional. NUMAlink is the CPU/router interconnect.

XTown2 is the interconnect for I/O (i.e. from C/R-brick to I-brick, 
G-brick, X-brick, P{X,E}-brick). It runs at 1.2GB/sec bidirectional and 
is pretty much "external XIO". Most bricks have two XTown2 connectors on 
them.

The Origin 3000 architecture is insanely cool. The other neat thing is 
that hardware-wise the Altix systems are basically Origin 3000 systems 
with different CPUs. And the Origin 300 and Tezro both use identical 
ASICs etc, as the larger systems, they are just packaged differently.

> Unlike their O2000 pages which lists the memory bandwidth, the O3000
> site only lists the aggregate bandwidth.

Peak local memory bandwidth on Origin 3000 is 3.2GB/sec IIRC.

> Need more info.
> 
> Man, I'd like to work on one of these.

We have a baby Onyx3 (only 8p + 1 g-brick) and an Origin 300 at $work, 
along with a couple of Origin 2000 systems. Its nice gear to use.

Cheers, James