Re: How many times must Apple make such DRASTIC architecture changes?

[Tim Cutts <timc@chiark.greenend.org.uk>]

In article <11ah0pqdup2vq4c@corp.supernews.com>,
Laine Houghton <laine@intergate.com> wrote:
>
>Aren't OS's being written and tested on the IA-64 and AMD 64 at this moment?

64-bit OS's have been around for a long time, but not in the mainstream.
DEC alias Digital alias Compaq alias HP created the Alpha back in the
early 90s.  That has had a full 64-bit address space for years.

As to the IA64, it actually has a 50 bit physical address space (I
think).  I have an SGI Altix at work which has 192 GB of RAM, in a
single operating system image, and which a single process can access in
one go.  SGI have built much larger machines for some customers; I
believe there is a *single* machine in Japan with 13 TB (yes, terabytes)
of physical RAM.  The SGI cluster NASA are building is a cluster of
larger Altixes, in terms of CPU count, but they don't have as much
memory per node.

As far as I know, no-one except SGI currently markets machines which can
take as much RAM as this.  Compaq used to - our Altix' predecessor
machine was an AlphaServer GS320, which also had 192 GB of RAM.

Tim