[geeks] anyone know about this? 72-core, 48GB computer?

[Joshua Boyd]

On Thu, Oct 01, 2009 at 08:07:10PM +0200, gsm at mendelson.com wrote:
> On Thu, Oct 01, 2009 at 01:32:50PM -0400, Joshua Boyd wrote:
>>
>> I don't think that the SC machines are single system image.  I think
>> they run an image for every 6 processors.  I don't know that for
>> certain, but for their biggest system, they have more processors than
>> the kernel trunk supports.  Also, they repeatedly refer to the machines
>> as a cluster.
>
> That makes it less impressive to me. As a deskside computer, it's
> interesting, but isn't it just like the SGI machine we just poo-poo'ed
> with non standard processors. 

I poo-poo'ed the SGI for almost literally being a fancy case for off the
shelf boards, and failing to bring anything new to the party, unlike the
cray system, which makes infiniband standard and offers a nice mix of
graphics and tesla options to go with the computer blades.

However, in addition to liking MIPS, this system uses a proprietary
interconnect which could be interesting, if for no other reason than the
somewhat odd connection graph (Kautz) that appears to be made of
interconnected rings.

It is also possible that there are nice instruction set properties
compared to Atoms.

> As much as Intel processors are un-interesting at least they are standard
> and which makes them well tested and easy to find skilled programmers for.

Finding people skilled at writing HPC software is hard enough that
writing for Intel versus MIPS versus PPC versus something new is little
difference. 

>> Last I heard they had passed 75 machines shipped.  75 of the little ones
>> is not at all impressive.  75 of the medium and big ones seems like a
>> reasonable volume, but obviously it wasn't good enough.
>
> My guess is that they had a batch of boards made up and stuffed them in 
> as many machines as they could make. When it came time to find funding 
> for another batch, no one was interested. :-(

Or at least no one was interested in investing the money in advance of
getting hardware.

> Personally, I'd love to see a quad core ATOM (which I assume is in the
> pipeline, but that's pure speculation) on a little board that plugs into
> a backplane. Then you could do the same thing with processors that  
> everyone knows and loves. 
>
> You could even start out now with single or double core ones and replace
> them as needed/available.

You would also need to add in a PCI-8x infiniband controller, or
something else like myrinet, or something new.

> Of course, you could just buy a bunch of ASUS EEE motherboards, with a  
> rack type power supply and a 1000BASE-T hub in a cabinet to make a proof 
> of
> concept unit. :-)

You could, but it wouldn't prove much.  It would only be interesting if
you used a fancier interconnect.