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Re: Do I need 64Bit if RAM is more than 4 GB?

On Wednesday 08 September 2004 15:42, Ron Johnson wrote:
> On Wed, 2004-09-08 at 15:03 +0100, Paul Brook wrote:
> > On Wednesday 08 September 2004 14:45, Ron Johnson wrote:
> > > In fact, it seems to me that *any* 32 bit processor (SPARC, HPPA,
> > > Power) that wants to be able to use more than 4GB of total RAM
> > > would have to use such a segmentation scheme.
> >
> > Err, all of the above have 64-bit variants.
> Yessss, but they didn't *start* with 64 bit variants.

Actually Power did. It was designed as a 64-bit architecture that can also be 
run/implemented with only 32-bits.

> >                                            I don't know if the
> > 32-bit variants support more than 4GB ram, but I doubt it.
> Oh come on.  You think the SPARC32s, Powers & PA-RISCs that ran
> big Solaris, AIX and HP-UX SMP boxen in big shops *never* had more
> than 4GB of RAM?
> I find it supremely hard to believe that Intel is the only company
> to have a 32 bit chip that can address more than 4GB of RAM.

Well, sparc64 has been around an awful long time. Adding PAE-like hacks seems 
a strange decision when you have backwards compatible 64-bit CPUs.


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