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Annirak · 11-22-2005, 05:20 PM

There's a few things that confuse me here. It's going to take me a while to get to the relevant point, but I will get there, don't worry.

For a closed system, power in *must* equal power out. That's a fact we know for sure.

Next, given a set flow-rate, and a set airflow through a rad, it's easy to characterize a radiator's performance. We know that too.

Given that knowledge, we can characterize the heat added to a system by the pump, friction, turbulence, etc. That heat can also be characterized by insulating the pump, and measuring it's power dissipation (closed system again here).

Would it not be easy to measure power into a system by measuring the temperature change across the barbs of the radiator, the ambient air temperature, and the coolant flow-rate?

Given that measurement of coolant temps is easy (used everywhere in industrial process control) and so is flow rate (if you want to pay for it, and have the space), how hard would it be to characterize full die->coolant performance--which is all we should care about anyway? I know the on-die CPU diode is not the best measure out there, but it's better than nothing, which is where we are now.

If a worthy tester was willing to grove the IHS of an actual CPU, the thermal output of the system can be characterized off of the radiator. Given the CPU diode and the IHS measurement, the quality of the IHS contact, and the thermal resistance could both be characterized for any given WB.

Others have said it, I'll say it too. The temperature of the IHS doesn't mean a thing to me. I care how well the whole system works together.

We need wholistic testing because--really--who cares if the IHS is a few degrees colder if the CPU keeps overheating and crashing?

11-22-2005, 05:20 PM	#245
Annirak Cooling Neophyte Join Date: Nov 2005 Location: Over There Posts: 37	The part I don't get There's a few things that confuse me here. It's going to take me a while to get to the relevant point, but I will get there, don't worry. For a closed system, power in must equal power out. That's a fact we know for sure. Next, given a set flow-rate, and a set airflow through a rad, it's easy to characterize a radiator's performance. We know that too. Given that knowledge, we can characterize the heat added to a system by the pump, friction, turbulence, etc. That heat can also be characterized by insulating the pump, and measuring it's power dissipation (closed system again here). Would it not be easy to measure power into a system by measuring the temperature change across the barbs of the radiator, the ambient air temperature, and the coolant flow-rate? Given that measurement of coolant temps is easy (used everywhere in industrial process control) and so is flow rate (if you want to pay for it, and have the space), how hard would it be to characterize full die->coolant performance--which is all we should care about anyway? I know the on-die CPU diode is not the best measure out there, but it's better than nothing, which is where we are now. If a worthy tester was willing to grove the IHS of an actual CPU, the thermal output of the system can be characterized off of the radiator. Given the CPU diode and the IHS measurement, the quality of the IHS contact, and the thermal resistance could both be characterized for any given WB. Others have said it, I'll say it too. The temperature of the IHS doesn't mean a thing to me. I care how well the whole system works together. We need wholistic testing because--really--who cares if the IHS is a few degrees colder if the CPU keeps overheating and crashing?