64-bit Processors

[Karen Spearel]

dsavage at peaknet.net wrote:
> On Friday February 20, 2004 "Timothy J. Miller"
> <tj.miller at javaspotlet.com> wrote:
> 
>>Question re: the AMD line of Processors, I currently am considering
>>updgrading a machine and am looking at the AMD Processors. Is there a
>>way to tell which are 64bit and which are 32bit?  For example, is the
>>AMD Athlon XP a 64 bit processor or a 32bit?
> 
/snip
> 
> With all due respect, if you are asking this question, I don't think you
> should be thinking about upgrading to 64-bits just yet.
> 
> --Doc Savage
>   Fairview Heights, IL
> 

I'm not sure I agree with this advice unless one is on a strict budget. 
  The Athlon 64 3200+ runs all releaased and current testing versions of 
Fedora here without any problems....and never had a problem with the 
standard 32 bit versions.  My son has been gaming under Windoze with his 
Athlon 64 3000+ for more or less continuously without a BSOD since 
Christmas, a rather remarkable thing.  The Athlon 64 motherboards tend 
to be rather expensive, but the extra bucks tend to buy you a certain 
level of quality.

My disagreement is basically that if the OP is comtemplating building 
his own system, dealing with an Athlon 64 mechanically is much less 
prone to error than are any of the 32 bit Athlons.  Heat sink/fans are 
very critical to reliable operation of the Athlons and all the 32 bit 
Athlons are also subject to mechanical breakage when in the hands of the 
inexperienced.  The heat spreader on the Athlon 64 and the general 
mechanicals of the Athlon 64 motherboards make them much less prone to 
mechanical or thermal damage in the hands of an unseasoned builder.

If on a budget, the XP 2500 is pretty hard to beat...but if one was 
comtemplating something in the range of 3000+ or 3200+, I would consider 
the Athlon 64 to be the way to go.  Regardless, buy the biggest 100% 
copper HSF/fan with at least an 80 MM fan your budget can stand.

There is one caveat...the Athlon 64 BIOSes require matched DIMMS if you 
are ever comtemplating running 2 DIMMs and the Athlon 64 does not seem 
to like running at full speed (200 mhz fsb) with high latency memory 
when the memory bus is fully loaded (i.e. with 2 DIMMs).

In my experience, Athlons aren't fussy about using generic PC3200 DIMMs 
but the Athlon 64 ***is*** when running with a pair of DIMMs...the 
current Athlon 64 stepping only handles 2 unbuffered DIMMS at a 200 mhz 
fsb and then only with fast memory.  If you go with the Athlon 64 (not 
the FX (which is really an Opteron where you have use registered DIMMS 
thereby correcting the signal skew problems)), I highly recommend 
finding some 2:3:2:6 or faster DIMMs.  An Athlon 64 system with slow 
DIMMs (i.e. 3:4:4:7) may not be rock stable with a 200 mhz fsb.  You 
have been warned. :)

This is prolly OT so I will shut up now.

KAS