Paul,
I am relatively new to SMP Linux, but I can tell you that Linux ( even
uni-processor ) is still in development on SGI. Apparently it only works
on the Indy platform, which would not suit your needs. My understanding
is that the only two platforms that are capable of stable Linux SMP are
Intel and Sun, Sun being the better platform due to the SMP friendly
design of the hardware. I do not know the maximum number of processors
supported on Sun ( sorry ). I personally like the Enterprise 3000 model
from Sun.
I realize that this response is full of "apparentlys", "my
understanding", and "I don't know". I am not a master of Linux yet, my
specialty being Solaris ( decent os ), IRIX ( it's gotten much better ),
and AIX ( gulp! ). I hope, however, that some of the Linux guru's can
expand on my answers and smack me down where I am wrong. :-)
Regards,
Timothy MacDonald
System Analyst
Landmark Graphics
Houston,TX
[EMAIL PROTECTED]
> -----Original Message-----
> From: Paul Komarek [SMTP:[EMAIL PROTECTED]]
> Sent: Tuesday, December 01, 1998 11:55 PM
> To: [EMAIL PROTECTED]
> Subject: Big SMP
>
>
> Okay, my advisor has settled on our small machine: a quad Xeon with
> 2GB.
> But now he's working on the proposal for the big machine, and guess
> who's
> going to do the groundwork.
>
> So here's the question: How big can Linux SMP get? In particular,
> how
> many processors, and does it depend upon which architecture? It isn't
> enough to know what the kernel can support, I need to actually find
> supporting hardware. We are more loyal to Linux than anything else,
> but
> can we get eight or sixteen cpu SMP hardware for Linux to run on? How
> about 32 or 64 cpus?
>
> Also, I've tried to find results about the expected diminishing
> returns of
> many cpus in a regular SMP setup. I assume this occurs because of the
> cache coherance traffic on the shared bus. Are there some
> architectures
> on which Linux SMP works that get around this with multiple or special
> busses? Otherwise, what kind of SMP-like support is there under Linux
> for
> machines that aren't strictly SMP? For instance the SGI Origin series
> isn't an SMP architecture, but the ccNUMA support from the hardware
> and
> a special version of Irix make it SMP-like (at least according to the
> promotional literature).
>
> For a sense of scale in the grant proposal, I'll say that my advisor
> was
> initially interested in the Origin series--except that SGI charges way
> too
> much for memory and hard-drives (we need _at_least_ a terrabyte of
> storage, maybe two). And the main memory should be no smaller than 32
> GB,
> though 64 GB is desired.
>
> In particular, ease of programming is the most important feature. We
> would like to avoid message passing for now. Threads are the
> preferred
> option, but forking (does clone() with shared memory work in any SMP
> or SMP-like configurations?) is fine too.
>
> Obviously I'm no multiprocessor guru, but I'm willing to work towards
> that
> end--if someone can point me to information which has some nonzero
> probability of being helpful, I'd be grateful. I've spent a lot of
> time
> on manufacturer's web sites with very little to show for it, so I'm
> willing to follow any new lead.
>
> -Paul Komarek
