Mr. Adams that was me btw not pH :p people kept on asking who the hell you are. You can't say its entirely inaccurate :)

Don't look at me (I have a set of keys but I don't have a parking spot).

Can't argue with cross platform issues; your simulator is much better for that. I will eventually move to a quality die simulator. No question about it. Even with your setup though you could argue about effects that choice of die size have upon cross-platform extrapolation (that area affects the limiting baseplate/die junction, right?). Also don't know that lesser simulators (resistors on a piece of copper) are all that much better than a CPU (would be if it were simply a constant % lost, but is this the case?)

not gonna win an argument with the owner of the sand box
but stank was ok, intolerant perhaps more accurate

Joe
as one who also tests wbs, take a look at this thread
comments ?
it would be helpful to establish a level playing field

Make'n me reg on those forums.. damn you!!! I have avoided it all this time!

pHaestus
and here I was thinking 'at the right hand of god, et all . . '

one could say mine is a resistor as well, just with a WHOLE bunch of attention paid to the details
the die area relates to Watt density, P4s (or those other big Intel things) are, like TECs, different
how different ?, no data
but I chose 10x10mm as a middle ground for AMD

getting some bad news re the new setup
it takes FOREVER to come to equilibrium, as in 1.5 to 2 hours per change
s**t

Joe
a couple of ok posters there
and a good idea knows no source

I am very concerned with the low numbers that come from JoeC's simulator since I am getting values substantially higher with the diode reader when you take AMD's estimates on W. That is, at the moment, really lowering my interest in using a similar type simulator (and I can't afford the setup you have; even the power conditioning, monitoring, and supply is out of my price range). So I figure that I can have some fun playing with how system variables affect heat production (you know you want to see it too) and then choose a suitable suite of stresses to run when testing blocks for the current AMD platform. Modest goals...

Doesn't that mean that it ALWAYS took that long to come to equilibrium, but you can only now observe it? Resolution has more prices than just the equipment cost.

Bill I replied, I like the idea of a standardized test, but the real fact is that there would still be hundreds of variables that people would need to figure in when comparing a test even if ambient was the same. Although it is better than nothing ;)

Even between die simulators, testing would still be quite different between site to site and person to person.

Also... we need a real watt app for how many watts of heat these CPU's put out at the different voltages... Radaite doesnt cut it... This is not for testing but so that readers can relate the "real watts" from a calibrated die simulator to their setup.

Joe

re the die simulators
the better they are made, the closer they will read
good = accurate
any simulator uses a source which are all instrumented exactly the same (I use HP and Fluke stuff), and the wb is the sink
as the level of sophistication increases, the differences will decrease; got to be
a 'problem' is the die face, the silicon chips (per the Big Boys) are the std, but out of my league

I'll defer to pHaestus re the CPU stuff, don't do it, don't know it, never have
and the more I learn (from others), the less I like it
but the CPU is what people have so thats what they are going to want to use, no argument

pHaestus

is there some software program that loads ONLY the CPU ?
correlating such would be no problem
have our cake and eat it too

"Doesn't that mean that it ALWAYS took that long to come to equilibrium"
yes, and no
along with the uniform 0.01^C resolution change I also increased the die simulator insulation and added embedded RTDs, so now I'm looking at internal insulation temp trendlines that previously were simply higher losses
the wb stabilizes at 1.5 hrs, the die at 3 hrs (but only a 0.1^C change in the last 1.5 hrs), whew
gonna have lots of time to post with the nightowls

Probably have to skip programs like Prime95, Seti, Folding@home that have an actual purpose. Those all offload info to hdd and memory regularly. AMD has an internal program that supposedly is similar to Intel's MAXPWR program that only loads processor and to 100%. I suspect that such programs will have to be tailored to the cache of the processor, and then they just send it off on some endless loop. K7Burn seems to be the closest thing to this I can find, but I don't have the resolution (for another few days) to really check that.

Just like the die simulators, this is quickly going to move away from what "feels good to end users". Any monitoring equipment should be on a separate PC; don't know too many overclockers doing this though. Probably a good many more nights of discussion and thought (not many do that either).

Embedded RTDs in the simulator? Looking at heat flux through the unit? Lots of temps needed for that...

"monitoring equipment should be on a separate PC"
yep, I did not think of that - got to be

will/can your reader be setup as a stand-alone unit ?

"heat flux"
mercy no, just looking at the trend of the gradient through the insulation

with the test series taking so long I suspect that the AS2 could be an influence
perhaps I should change to dielectric grease (works about as well)

The eval kit from Maxim connects to a parallel port and will happily run on a pentium class notebook for logging/monitoring.

It's kind of frustrating to think that AMD already has the answers (or at the least much more insight) to all of these sorts of questions (and many more). At least Intel makes MAXPWR available.

So I assume I will have to contend with your voice chanting "oooohhhm" the entire time I am testing out different programs, fsbs, ram amounts, and the like?

Looks like the original posters have all fled for higher ground. Was this thread even originally about testing?

I agree, but hardly any site that CAN afford to buy a few grand in testing gear would, and all the sites can cant, wont. I mean setting a "standard" testing level to the point that its unrealistic to 90% of the sites out there to buy is a bit impractical and would do an injustice to the readers just as much as not having a standard does.

What needs to come out is a "standard" that is economical, yet effective and accurate to a tight tolerance. I mean do readers really need .01 or .001 Accuracy? Will .02 C make a HSF that much better or worse than the other one? Not saying the more accuracy is not better, but I am saying is it really needed/practical for the hardware that’s being tested on the web?

I think a "standard" is a pipe dream that in all reality will never happen between more than 2 or 3 sites on the web... For the simple reason that any time a website posts numbers that are different from the norm, instantly readers think the review is bunk and not considered correct. Hell the owner of KDComputers questioned my testing for weeks after I showed that POS CPC 370 HSF sucked! he even bough a Extech thermometer, to duplicate the test on his side ( since it was the first time I did a test with a T/C under a core like that it gave numbers far different than the oh so wonderful under the core thermistors. ) Many of the Bigger websites are afraid of that, damn afraid, and are also afraid of being found out that they have no clue what they are doing. Also the time it takes to REALLY test a handful of HSF's and blocks is not a day thing, its weeks of work, this is another aspect they don’t seem to gather.

I am just off on a rant at this point so I am going to go to bed... I would just like to remind everyone.. I freaking HATE doing reviews... by far the most thankless part of doing anything on the web.

Gotta be careful though Joe: radiate and side mounted compunurses and C/W tables all originated from this same exact line of reasoning.

I think that you let the readers come to realizations at their own speed. I remember when I saw your "CPU back" measurements complete with dremel on the socket and epoxied thermocouple that I really realized how much hotter my TBird was than I suspected. So I soon did the same thing (with thermistor since I had a spare flat one). That wasn't a popular stance (as you mentioned), but it has to feel good to have AMD correlate diode to cpu back temps in technical documents later.

There are tons of untested ideas and theories relating to water cooling that require careful precision testing to really expose. The same questions pop up often on forums relating to system design and component choice (all forums are full of them), and there are plenty of responses but not much data and often the answers are hearsay or popular opinion more than anything else. The community needs testers who are interested and have equipment up to the task of proving (or more often disproving) some ideas. Thermodynamics isn't always particularly intuitive (especially to those with a non-technical background) and even though my background is decent the application and terminology are all different and still have a substantial learning curve. The need for reproducible numbers at acceptable uncertainty levels goes far beyond reviewing blocks I guess is my point.

Whooa. That took a long time to read. But it's a very interesting topic.
Here's my take on the "Do i measure all the different setups or do I make a simulated test on each type of component"

Say you want to compare 10WB, 4 pumps, 10 rads and 2 types of plumbing. That gives you 10*4*10*2=800 different combinations.
Versus running 10+4+10+2=26 different tests for the simulated test measurement setups.

I know you guys are putting alot of time and effort into these matters and I (fore one) really appreciate it. But I would not expect it from any of you to do measurements on 800 different setups.

So from this point of view the simulation approach is the only way to go.

There are of course a number of other factors that makes simulated measurements better, reproducability, better control of the variables etc.

Just my 2 cents

Its very difficult even in a lab to keep a level playing ground (I.e equilibrium) for a whole batch of testing.
But how accurate is accurate ?
You may spend so much time testing your test idea that the point is lost ?
As Bill has pointed out, secondary thermal transfers in a CPU do play a part in its cooling. Unless the die can also simulate this, then we are back to square one.
I would really like to see some form of standard, where we at least get some real temp figures from ppl who quote how well a certain component is performing.
I purposely never release any figures(temps) for my products as the only parts of the test that seems to be consistent is the amount of errors I believe I have.
I also use Fluke meters & thermocouples(K type). What I lack is a flow meter :( - so how relevant is any testing I do ? Only for R&D IMO.
Still my hat off to you guys, your efforts are valiant. I wish I had the time & resources to be able to do complete methodical tests of components. Can any of what you need be hired btw ? (just a thought, since purchase is highly expensive) .
Hell as a manufacturer I *should* pay for the data you guys generate - since it may help us(us as manufacturers) improve our products, or those that still read threads like this anyway ;)
I certainly look forward to the Method.

Please let me know what you think.
 

Alot of the dabate here has been around the issue of compairability of the different tests across the globe.
The problem with compairing person X results with Y's is the calibration of the measurement setup.
I've bee thinking about it for a while and this is what I've come up with as a part of a solution. Using a die-simulator and doing the measurements this way:

We want to measure how "good" the thermal interface between the cpu and WB is.
The problem with measurement of a WB is to know the exact amount of applied power and the effect of the pump/rest of system.
Therefore we must calibrate the setup.
First measure the exact amount of water in the system, se picture 1, we call this volume V.
Then run the pump without the cpu simulator on. For a half hour or so and measure the temps every 30-60 seconds.
The total time is depending on the amount of water and the C/W of the box/hoses. But the important part is that you measure untill the temp is stable.
This gives you a calibration curve/plot to correct our measurement with. The plot will/should look something like picture 2.
Now we can calculate how much power, P_pump, the pump adds to the water by using the slope, K_pump, of the curve in the beginning of the measurements and the measured amount of water V.

P_pump = K_pump * theta * rho * V (Watts)

(rho = 1kg/litre = desity of water)
(theta = 4180 J/(kg*C) = specific heatcapaciy of water)

A typical pump (eheim 1250) consumes 28W. With a setup with one litre this should give us a slope of K_pump=0.0067 C/s.
1/K_pump=150 s/C = it takes 150 seconds to heat one litre of water one degree celsius.

Now wait untill the water reaches ambient again and redo the temp measurement but with the cpu simulator on and measure the power it consumes.
P_cpu=U*I

Now we know the total applied power P_total=P_pump+P_cpu and the WB C/W of the system is easily calculated using the equilibrium temp at load.
If we take the slope in the beginning of the load measurement, K_load and subtract K_pump we get K_wb.
To calculate the C/W of the WB we need the temp at the cpu simulator an ambient temp:

(T_cpu - T_ambient)/((K_load - K_pump)*4180*rho*V)=C/W of the waterblock


If we want to compare different measurements from different places/persons we do:
EXAMPLE
Lets say person X measures a MAZE and a SPIRAL and person Y measures a MAZE and a SWIFTECH. Both persons has done the measurements the described way.

Person X:
MAZE_X=0.40C/W
SPIRAL_X=0.35C/W

Person Y:
MAZE_Y=0.55C/W
SWIFTECH=0.50C/W

Which is better SWIFTECH or SPIRAL?

SPIRAL_X/MAZE_X =0.40/0.35=1.14
SWIFTECH_Y/MAZE_Y=0.50/0.55=1.10

Since the SPIRAL har a relative difference that is bigger than the SWIFTECH the the SPIRAL is better.
(PLEACE NOTE THAT THESE NUMBERS ARE MADE UP AND IN NO WAY RELATE TO THESE WATERBLOCKS, i simply stole the names to make it easier to read)



The same setup can be used to measure different radiators. By simply exchanging the WB with a rad and heat up the water to, lets say, 60 degrees celsius.
Do the measurements like above, with/without fan on rad, to get the K values, the slopes in the beginning, and then calculate the C/W th same way.
(what about the fan some might think. Well if you use a monster fan that "saturates" the rad = any higer airflow won't make any difference,
then the rad is working under optimal/best conditions, then the airflow will not reflect on the measurement).



What do we need for this to work = conclusions :
To compare we need a WB/rad that both persons use as referense.
Since all comparisons are relative the difference between systems are irrelevant.
Since the calibration is made, the relative K_WB is indifferent from different setups.
We need good isolation around the reservoir to get a big delta temp.

Now I'm beginning to get tired and I've probably missed something somewhere but please look at the idea as a whole.

ok here is pic 2
 

forgot pic 2

Dix:

Yes I agree that you have to have a block or two as "standards" that you retest every time you break down/upgrade/change your system. I used a GLaciator2 and a Dynatron BH610 for this purpose when testing heatsinks a while back. It is the only way to have any confidence that your numbers are not being affected by some experimental error. Your proposed setup isn't so different than Bill's except instead of an insulated box he is using a lab chiller for his submersible pump and controls the set temperature so that it always results in an inlet water temperature that is constant. You'd really need more temp probes :) but the advantage of your design is that you could cheaply find a digital thermometer with type Ks that has two inputs (Ex Tech?). The problem is the time required (I suspect) to come to an equilibrium, and the fact that different blocks will have different restriction amounts, and so the pump will generate different amounts of heat (how to correct?). Flow rate data still needed, and also much more tedious for this since your pump will become more and more important in heat generation.

The thing that Bill and I have been kicking back and forth here is that most of the die simulators (Bill's excluded) seem to still have substantial secondary losses as well (or else their calculated W isn't much better than radiate's). So you are back to only internally valid numbers; no comparison between testers is good since their error in W created vs. W applied is all going to be different anyway.

No comparison between different testers is ever likely to be good; testers might as well just shoot for internally good numbers and then explain their methods. The TIM between die and block is a huge variable, as is (for most) mounting pressure. I can probably get a consistent paste application over time, but I wager that it will never be the same thickness settled upon by other testers.

pHaestus:
Nice to see that somebody acually took the time to read it :-)

I agree on the timeconsuming aspect of it all, but if you choose a small amount of water. Then it will go faster.

However I think you missed one of the points with this setup, or i explained it poorly.
So here is another try:
1* Since you calibrate each WB to get the certain K_pump for that particular WB/restriction then the differences that occur in the pump gets cancelled out. No flow measurement needed!.
If you decide to change the flow with a restriction the you must recalibrate.

2* As you see i can extrapolate the power the pump is adding to the system. By measuring the deltaT, the time and the amount of fluid. This calculation is also possible on the second measurement and gives the total power added to the water by the simulator and the pump. Subracting the total power with the pumps gives you the exact power that the WB recives and transports to the water. If you at the same time meassure U and I to the simulator (SIM) you can caculate the losses from the SIM to the secondary heatpaths.

3* If we would isolate the WB and SIM from the sourrundings with a box the the WB would collect heat/power from the hot air inside the box which it normally wouldn't and it would perform better than in a real world application.
However you are correct that there is no way to compensate for the differences in secondary heatpaths with this setup and a real CPU.



More comments/ideas/thoughts anyone.

What I am saying is that the waterblock itself is a significant restriction, and will cause the pump to add a different amount of heat to the water for every single block tested. You can't account for this by testing the pump in the absence of the block; you can only hope to account for this by adjusting flow and monitoring it with a fair degree of accuracy. Bill might have some estimates on how much more heat a pump adds to water when throttled (actually I wager he does). The accurate measure of power into the system (from die and from pump) becomes a serious problem here IMO.

Read it again and you will se that the WB is there during the calibration and therefore any difference in the pump between two different WB is cancelled out.

The only difference between the actual measurement and calibration is SIM off or on. No changing any physical parameters.
Thats why its called CALIBRATION.

Ah ok. Gotcha. I still think you would have to do multiple flow measurements or else you would get skewed (pump dependent) results in terms of relative performance. I have another question though.

If you have a constant heat input (a CPU die real or simulated transferring heat to the water through a block) and a completely sealed and insulated reservoir (that contains water and a pump), aren't you going to just constantly add heat to the system until parasitic losses take over? What makes you think this would be a situation that you could easily find an equilibrium value? I would think for equilibrium measurements you would have to have a heat exchanger for the input of heat to come to equilibrium with or else wait REALLY long times (and end up with extremely high water temperatures)?

The point with the islolation is to delay the parasitic heatloss to the surroundings.
The numbers we are interested in lies in the begining of the measurement = gradient of the slope. And not in the end where we reach equilbrium. The isolation makes th initial gradient appear for a longer time and therefore contributes to a better result.

If we, lets say, add a rad to the system it will reach equilibrium much faster and at a lower temp which gives us less data to correctly approximate the slope in the beginning of the measurement. A chiller is the total killer for this type of measurement because it regulates the water temp actively and that way destoys the gradient we are interested in.

Dix Dogfight

don't think so, your method is mass dependant and a wb could be designed just for the test
look at some of Jeremy's comments on OCAU re just this point
AND you are summing the effects of a number of variables; are you quite prepared for the math involved with multivariate analysis ?
- then you would have to validate your test by testing just that parameter under observation

why not test just that variable to begin with ?

and I REALLY do disagree with looking at a transient response, not the way its done

but give it a whirl, try it

a question: can a circuit analysis be done with no reference to current ?
nor can you evaluate a heat exchanger without reference to flow

unregistered:

Well the mass or volyme of the water needs to be measured to extrapolate the C/W but that is the total mass of all the water in the system so i can't se how you can produce a WB that works better with more water in the system.

The problem all you WB testers/reviewers are facing is a combination of poor equipment and difficult testingparameters.

What do we need do calculate the C/W which is the common way to compare the performance of different WB.
We need the Power/heat that is injected into the water through the WB and the difference in temp.

Injected power is hard to measure because you don't know the secondary cooling (mobo and air around socket).
Temp is hard to mesure because we can't afford to by calibrated instruments etc.

So we use poor tempmeasurment devices and guestimates the powerinput.

Now tell me. Where does the measurement of the flow make any of those measurements better?

The setup I am proposing here uses the same crappy temp measuremend device but by first calibrates the setup and then make a relative measurement. Any temp offset/unlinearity in the probe will be cancelled out. As a bonus it is possible to extrapolate the exact amount of incected power into the water. And that also tells you how big your secondary heat/power-losses are if you at the same time measures U and I to the SIM.

"Transient response, not the way to go."
Why not when it works?

Some one once said:
If it's stupid but works it ain't stupid

different situation here
don't use a CPU to test with
have good equipment
its calibrated

I'm not into guessing, I measure

"The setup I am proposing here uses the same crappy temp measuremend device"
not worthwhile, gigo
can't make a silk purse from a sow's ear

if you already know its crap, dump it for something that will be effective

but you need to address the methodology

The methodology is EXACTLY what iv'e adressed with this proposal.