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

On Wed, Sep 08, 2004 at 04:09:59PM -0500, Ron Johnson wrote:
> http://www3.sk.sympatico.ca/jbayko/cpu5.html#Sec5Part4
> "Part IV: IBM RS/6000 POWER chips (1990). . . ."
> "Thirty two 32-bit registers were defined for the POWER1 integer 
> unit, which also included certain string operations, as well as 
> all load/store operations."
> Blah blah blah POWER2
> "It was superceded by the POWER3 (Early 1998), with eight functional
> units (two FPU, three integer (two single cycle, one multicycle),
> two load/store, and branch unit), but capable of operating at much
> higher clock speeds. In addition, a 64 bit version, the PowerPC 
> A35 (Apache), was designed for the AS/400 E series"
> So, the first 64 bit POWER chips arrived 8 years after the 32
> bit versions.

1998 seems like a fairly resonable time to start getting into 64bit.  I
guess it does indicate the power wasn't designed as 64bit to begin with,
but seems to have been designed well enough that extending it later was
reasonable to do.

> > Well, sparc64 has been around an awful long time. Adding PAE-like hacks seems 
> Since 1995.
> There were largish SMP SPARC32 boxen for many years before the
> SPARC64 came into existence.  I can't find any references on the
> web, but some of those big boxen had to have more than 4GB RAM.

I wonder how much 4GB ram would have cost in 1995 or even 1998.  I
remember getting 16M for a 486 for $600 in 1992.  I think it was 1996
when I got 128M for about the same amount.  The price lists I found once
for Decstation 5000 boxes had ram listed at around $50000 for 128M in

Even in 1995 4GB would have been a rather expensive amount of ram even
for a high end sparc or power machine.

Len Sorensen

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