[bigben2k]

I can see that my comments have kept a few people up late...

Powerhouse, I think you've got a couple of misconceptions.
(so I'll list what I see, and you tell me if I'm wrong!)
1-Although water temperature is a factor in the performance of a waterblock, controlling that temperature is not something that is a part of a common water cooling setup (i.e. there is no chiller/heater). As a result, water temperature is irrelevant, for the purpose of testing a waterblock. If you don't agree, then look at it this way: if a block's performance was (theoretically) optimal with a coolant temp of 15C, what could you really do with that information?

Also, in your reply to pHaestus, you (essentially) stated that temperature should be tested as a function of flow rate, when really, it's the other way around. Water temp is not relevant, it's just a consequence.

In the same reply, I don't think you quite understood that the test of a WB would be performed at different flow rate with a fixed (read controlled) water temp (wether or not there is a rad is irrelevant), for the purpose of finding its optimal cooling setup. Selecting a rad is a separate issue, which makes my case for matching components.

Your frying pan analogy is funny, but doesn't quite match the number of factors involved in water-cooling. But just for fun: what if your frying pan had a thickness of 10mm? What if it was cast iron, instead of Aluminium? What if the stove was turned on 7 instead of HIGH? What if you matched a heatsink with a fan providing it with its optimal air flow rate? I think it would be of interest...

2-The heat dissipation properties of a waterblock do NOT change with the temperature of the coolant. The only situation where this statement would not be true, is if the temperatures would change the physical state/properties of the materials involved (i.e. tygon melting at 80C, water boiling at 100C, copper turning into liquid at 2500C, etc... I know that it's hard to believe.

Now I'll answer some questions/post comments...

PH: you suggested "comparing the difference with the new CPU and adjust all you numbers accordingly". Now you're talking about a lot of expensive gear!!! Keep in mind that this gear CANNOT change from one test to the other, so if something fails, it would have to be replaced with EXACTLY the same components, which may or may not be available anymore. Also, some gear fit for an old Duron, may not even be appropriate for an Athlon Xp, and vice versa.

PH: about load testing low/medium/high
Unnecessary, and too time consuming. it would be far simpler and more accurate to measure the performance of each component individually under ONE typical environment.

About reviews/tests: if all you're going to do is ignore the numbers (which is fine) and take several people's opinions on which is best, then that'll work well, for air cooling. For water cooling, there are several components available together or seperately, but the best of each will not yield the best results.

About the time it takes to do the tests:
I would trust a test if the testing methods were consistant, and gave me usefull numbers, REGARDLESS of how long it took. The method/results speak for themselves. How long it took to get those results is IRRELEVANT.

About pumps:
This is one point that you do have, in that tests don't match real life. e.g. if an optimal flow rate has been established at Xgpm for a particular configuration, there may or may not be a pump available to reproduce the exact flow rate. Pumps do perform differently based on the flow resistance of a rig, but this can be equated with the "head" rating of the pump, and so, you already have all the data you need. (actually you'd still need the net flow resistance of a particular setup, see below)

About rads:
as the OC review suggested, there may be a "sweet spot" to most rads. Wouldn't it be nice to know what they are for each rad? Or at least how to find it?

About different rigs:
My point is that you may be able to reach the same results, with a completely different rig.

About results:
There are a number of conditions that would affect an actual rig, and those include: tubing length (not size), actual volume of coolant, coolant additives, number of elbows, ambiant temperature AND humidity, placement of radiator, effective rad fan flow rate, etc... but those are simply beyond anyone's control. Knowing that though, basic recommendations can be made, but otherwise, all those factors add up to establish THE ACCEPTABLE MARGIN OF ERROR of any test. Sure 0.1C temp testing accuracy would be nice, but is it necessary?

About the Maze-3:
It may not be a significant factor, but the interior is sandblasted, giving it a higher surface area.

pHaestus:
Your testing rig sounds very nice. The importance will be with your testing methods, as they have to remain consistant. It may be atypical, but a typical person would not get a flowmeter, pressure gauge, and many temp sensors, they'd just use the same gear, but straight out.

pHaestus: I like your graph... It'd be nice to see the data on a wider range though (take those results, determine a range that is of interest, then exceed it at both ends by 25%). so 3 GPM (180 GPH) would be pretty good for a MCW 462U, huh?

myv65:
You've nailed it right on the head. There is a temperature point where the wb will not cool under, regardless of flow rate. What I'm wondering is, if there's a sweet spot for rads, could there be one for WB?

About this discussion: there is one very important factor that has barely shown up:
MONEY!!!
In any company, when a project comes up, there is a cost study made, for the "best bang for the buck". Here, the consumer is the company...
My point is this: you could spend an outrageous amount of money on a water cooling rig, but you may never be able to sell it, simply because it's not cost efficient.

Would anyone really buy a solid silver block, with 3/4 inch barbs?