[Info-vax] If I wanted to get there, I certainly wouldn't start from here

[johnwallace4 at yahoo.co.uk]

On Jan 20, 6:31 am, JF Mezei <jfmezei.spam... at vaxination.ca> wrote:
> dool... at snowy.net.au wrote:
> > For any X32 systems that are running up against the 4GB memory limit,
> > then an upgrade to X64 is probably the safer option, but no longer
> > cheaper,
> > while the upgrade to IA64 will provide better performance and
> > scalability.
>
> Why would IA64 blades be any more scalable than 8086 blades ?

I wondered that too.

>Aren't
> blades relatively simple "computers on a board" and putting multiple
> blades in a box gives you multiple separate computers as opposed to one
> large multi processor box (like Galaxy class machines or HP's superdomes).
>

I was under that impression.

> And with the 8086 now at 64 bits, has it not broken free from the 4gig
> memory limit ?

It has indeed. You can get a Proliant with 512GB apparently. Not quite
the terabytes you can get on a high end Integrity, but surely you'd
have to be a little odd to want even 512GB of single-instance Windows
system, whether it be IA64 or x86-64? You could of course do lots of
separate x86-64 blades totalling terabytes, but that leads us back to
your earlier question, why would you choose IA64 for that?

>
> I am curious to know why independant customers would really choose IA64
> over 8086 to run Windows. (by "independant", I mean customers who don't
> get special deals from HP to get free IA64s in exchange for some
> publicity, as has happened to large supercomputing sites).
>
> Considering that Windows on IA64 has a very very small subset of
> applications compared to Windows on 8086, unless your application makes
> intensive use of a type of calculation where IA64 is better than 8086,
> are there really any benefits to running Windows on IA64 ?

Windows on IA64: Massive FP compute requirements? Terabytes of memory?

Have a look around from MS's "Windows on IA64 page [1] if you haven't
done so already and see if anything there answers your question(s).

Or maybe as you noted, IA64 just gets you a big 64bit Windows box at a
very very very attractive price supported by Intel/HP marketing
funding?

[1] http://www.microsoft.com/servers/64bit/itanium/overview.mspx

>
> For Linux, much of the software is open sourced and you can send time
> recompiling it on IA64 if you really want it. But with the Windows
> software being proprietary, you don't have the option to generate your
> own binaries.

Indeed. Maybe some Linuxes and some packages even come prebuilt for
IA64, though http://www.ia64-linux.org looks kind of dated. Probably
not many to choose from (eg not Suse, not OpenOffice, to name but
two), but if you can get the source, maybe it doesn't matter

Interestingly, considering JR's comments about sys$unwind, it seems
there's already an IA64 implementation of Linux's libunwind, mentioned
up front on http://www.gelato.unsw.edu.au/IA64wiki/IA64_Linux - and
further research reveals the initial libunwind author was HP's own
David Mosberger, which I guess is the same David Mosberger formerly
well known in the Linux-Alpha world.