Jim,"It really depends on when and why it kicks in..."
You are right. That's why I conducted a little experiment
with P4-1400, with the boxed heat sink (fairly huge one).
In open air at 23 deg.C, the whole thing runs relatively
hot, 45 deg.C, every part of the mainboard, including
RIMMs, when running BURNBX, but the throttling was not
engaged. To make it happen I had to block the air flow
from the heat sink fan. The throttling kicked off
when the base of P4 heat sink was about 60-63 deg.C,
a condition that is hard to get in a real case, IMO.
The throttling itself was engaged for 1ms, and pulses
followed pseudo-randomly with a main period of about
5ms, which means that the average slow down was about
10%. The total board consumption on 12V power was about
5A, so the P4 was running at about 50W (assuming 0.8
-0.9 efficiency coefficient for the core power converter).
When running regular Windows stuff like Media Player,
or Bytemark, it consumes less than 3A.
So, with the Intel stock heat sink, it seems like it
serves an emergency purpose only.
Regards,
- Ali
P.S. Forgot to add that the throttling was perfectly
reversable. Sorry about that. |
