Nadeem wrote:
> rms wrote:
>
>> http://techreport.com/ja.zz?comments=7417
>>
>> rms
>>
>>
>
> The results sound awful. I wonder what they actually used to measure
> the wattage?
Presumably one of the many household-appliance-power-meter things. There's a
difference between running hot and being power hungry. The Prescott is both
(ie: runs hotter and uses more power than the Northwood), but judging from
these results the 90nm A64's are less power-hungry than the 130nm parts. The
jury appears to still be out on whether it runs hotter or not.
What really needs to be done is for someone (TectReport would be good, since
they already have a 90nm 3500+) to test the chips at a large range of
frequencies and plot the results. If the results look like (view with fixed
width font):
Power
usage
^
| **
| **
| ***
| ****
| **** +
| **** +
| 130nm **** ++
| ***** ++
|***** +++
| +++
| ++++
| +++++
|+++++
| 90nm
|
|
|
+-------------------------------------->
Speed
Then clearly AMD is going to be having the same problem as Intel scaling the
CPUs to higher speeds. Intel's additional problem was that the Prescott
started out being more power hungy even at the far left hand side of the
graph. AMD doesn't have this problem, so may be able to ramp better than
Intel has with the Prescott. The key thing to look at is if the power usage
for 90nm parts ever gets above that of 130nm parts. We now know that at
lower speeds, 90nm parts consume less power. So, if they ever get to the
point of crossing the 130nm part line (as shown in the ascii graph), then
it's fairly likely that they're going to hit the wall quicker than the
130's.
--
Michael Brown
www.emboss.co.nz : OOS/RSI software and more

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