Bob Friesenhahn wrote:
> On Mon, 16 Jun 2008, James Cornell wrote:
>>>
>> Both systems are using 2GB PC2-5300 DDR2 (667).  2.4GHz Intel Core 2 
>> T7700, 2.6GHz AMD Opteron 1218.  Both are using ECC capable memory as 
>> far as I know, though scrubbing on my workstation has been set to 8 
>> hours.  (Super mode) My notebook is a MacBook Pro so there's no place 
>> to configure ECC.  I believe the system bus speed is what makes the 
>> difference.
>
> It used to be that the clock speeds posted for AMD chips were not the 
> clock speeds at all but only an AMD estimate as compared with an Intel 
> chip.  Has that changed?
>
> Opteron requires different compilation than Intel in order to go fastest.
>
> Bob
> ======================================
> Bob Friesenhahn
> bfriesen at simple.dallas.tx.us, 
> http://www.simplesystems.org/users/bfriesen/
> GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
>
They don't do that.  The raw CPU frequency is what I posted.  The model 
is 1218, this looks nothing like "2.6" and there is no relational 
comparison, it's raw computing power.  Making literal comparisons of 
vendor processors must take into account the front side bus speed, the 
multiplier, the voltage, the nanometer process, and the amount of L2 
cache on die.

With dummy-oriented benchmarks, direct comparison by accident is 
somewhat easy.  Compare point for point what the software regurgitates, 
5.5 here and 5.5 there... though this might require a whole array of 
testing machines.  From my experience it used to be that AMD produced 
chips that were lower clock speed and frequency, but were on par with 
real world speed comparisons.  That day has long gone, things changed 
and from real world speed comparisons, faster clocked AMD processors, 
worth double the Intel counterparts for general purpose tasks are not 
faster than the Intel's.

The fact that hasn't changed is that AMD's cost to buy is cheaper, 
always has been, this is their only weapon against Intel.  For a smudge 
more you can get a CPU that's 33% (1/3) or more faster, so buying into 
AMD would only be for large installations or possibly for high-end, in 
the instance they ever beat Intel again to new technology that is.  They 
beat Intel to x86_64, hence the AMD64 notation all over the place.  
Intel "borrowed" AMD's specification, but AMD has done it their self 
before as well.  I fall into the "I want to support Sun and I bought 
before Intel availability" crowd.  Not to say this machine isn't good, 
but it wasn't an efficient acquisition now that I look back on it.

The times where naming was vaguely comparable was during the AMD XP age.

AMD Athlon 2500+ XP was 1.83GHz but in some tests felt like a 2.5GHz 
Intel.  (Don't quote me here but I suspect this was the aim, to bloat 
the model numbers to attract consumers)

James

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