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To: wanna_bmw who wrote (51741)	8/20/2001 1:19:29 PM
From: Ali Chen	Read Replies (1) \| Respond to of 275872

"The link you gave must not have gone to the right place. Instead I found a guide to the i850 platform. But no matter, because I think you are confusing the measurement for power dissipation." I am not confusing anything, you are. Read and learn.

To: wanna_bmw who wrote (51741)	8/20/2001 2:24:40 PM
From: Pravin Kamdar	Read Replies (3) \| Respond to of 275872

bmw, Current varies during processor use, so P=IV is not a valid equation. Instead, thermal designers use P=CV^2f, where C = Capacitance, V = voltage, and f = frequency. You're not seeing the forest for all the trees. Think about it a little. Pravin.

To: wanna_bmw who wrote (51741)	8/20/2001 4:45:00 PM
From: Bill Jackson	Read Replies (1) \| Respond to of 275872

wanna, You an engineer? What railroad? Power is equal to the voltage times the current, that's it. We have a DC system here and the measured voltage and current are fine as they are what the thing eats. Now if you put a scope on the power supply you would not see it do much other than DC, these spikes and stuff occur on the CPU. Probe assorted paths on the chip and you will see loads of current spikes of short duration, both high as well as low. The net result is that average current and voltage your meter measures. I suppose you could immerse it in a calorimeter and run it for a while and measure the steady state temperature difference of the water or other coolant you use to stop it from burning. Now as the chip manages the power it will use less. There will also be some variation in the power used by different chips from other batches/wafers/areas on the wafer at the same clock speed. Bill