Informal test results CPU 350 vs Apogee GTZ

I removed 3 posts that were made after my last post. If you don't understand why the test was done with a temp controlling chiller you don't belong in the thread and are trolling. Anymore trolling will get infractions.

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Originally Posted by gabe

Been uber busy all week working on major project, and I am shocked to see this thread reached 7 pages already.

Still working hard, and too busy to respond individually, it would take hours! Here is some additional info.

Stephen told me that he ran the chiller pump on full because he noticed how restrictive the 350 was, and he wanted to keep his measurements out of the asymptotic area of the curve (0-0.5 GPM - see for example http://www.swiftech.com/assets/image...e-TR_VS_FR.PNG). He likes to take his temp measurements in the "flat" area.

For comparative testing, it is not practical to try to reproduce a user environment with the chiller, because the PQ curve of our pump is too different from that of commonly used pumps (655, 350's etc). Knowing that we need to eliminate the single biggest variable by keeping the coolant temp constant, one needs to understand that if we wanted to mimic a user setup fairly in a comparative test, we'd have to measure the flow with an arbitrarily chosen loop setup, then disassemble the block, and match the flow on the chiller, then do that again for another block, then adjust the chiller pump again, etc.. it's simply too time consuming.

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But if you got the pressure drop over the block you could match that with the formula:
dP=rkQ^2 => k=dP/(rQ^2) ,(k=l/2) r=density of water Q=flow.
you could plot that into a PQ chart of a "regular" pump and figure out the flow through it (without tubes and tubes have low k). K is the same with any pump assuming non-laminar flow.
Then alot of these discussions wouldnt be necessary.

The testing by itself is very good.

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Originally Posted by santiagodraco

Let me ask the question a different way (and I may be misunderstanding Gabe's reply (the one he's linked).

It seems that by using the chiller certain testing peculiarities are introduced that would make the use of a "normal" pump inappropriate in some way (correct Gabe?). If that is the case, and the use of the chiller is to eliminate the variable of room temperature (another assumption on my part) then if we assume the room temperature is very constant (maybe not) wouldn't the use of a radiator eliminate that and allow the use of a readily available pump?

I guess what I'm getting at is the good old real world test scenario. All roads seem to lead back to the beginning :)

But let me say this. I'm not saying Gabe's tests don't have merit (and yes I am very aware of what the scientific method is and variables) but... I just can't seem to get it out of my mind that the lab you use Gabe seems to introduce it's own set of variables that might not be representative. Maybe I'm completely off base, and I can't quantify them well, it's just a feeling (and yeah feelings aren't very scientific :) )

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Even with a very well controlled air conditioning system you have 1-1.5F difference in the room temperature if not larger swings. Since our radiators rely on the room temperature for their heat transfer the differences between test can vary substantially.

But with a chiller holding the water temps to tenths of a degree you have the best constant between test. (This statement is not directed at any one person) Questioning to understand someone's test results is good for learning but questioning someone's methods unless you are more qualified to do the testing is just foolish.

If this kind of thread craping continues manufactures and independent testers will not want to share their results, who would. To spend the kind of time and money to do valid testing to only have unqualified people call them everything from a liar to a fool is not what this forum was built on. FUGGER pays large sums of money to keep this forum running so all of us have a place to share our passions and ideas so lets bring XtremeSystems back to the fair and balanced forum it is known for. just my $.015

riptide already said it wasn't gonna continue, and I am glad. Sig, that last paragraph you wrote could not have been written any better. It ought to be put into it's own locked sticky at the top of this forum.

Man, I've been to other forums, and some of the stuff I read there had me believing some very bad things. Things which I later learned on here were completely false and inaccurate. That is why I registered here in the beginning and is why I am here now. These scientiffic tests are what separates the fact from fiction. If we started arbitarily thorwing in just anything into the mix we'd have contradictory results and tests and it would be a mess.