Apogee from Swiftech...

[nikhsub1]

Originally Posted by Orkan

I have read the thread, but seemingly mis-interpreted.

I fail to see the correlation between the AMD->core joint, and the performance of a waterblock.

If you take the same CPU, with its borked IHS... and test two waterblocks... the amount of heat given off by the cpu does not change. The IHS interface remains constant... whether it is borked or not.

ie: the amount of heat a waterblock can remove from said cpu... does not change based on how well the IHS is bolted on.

WB performance vs IHS problems?
I don't see how the two relate. I understand that it makes getting an accurate temp reading more difficult, but I don't see how it relates to the performance of the block.

Exact same heat source, two different blocks. I do not understand how the heat source being screwed up in some way affects the WB's ability to remove the heat.

Because when an IHS is on for shit, each mount will further degrade IHS to core integrity, c'mon i don't claim to be 1/10th as knowledgeable as Bill, Cathar, pH, Lee, Les and a host of others, but surely this fact should be common sense.

[GlassMan]

Originally Posted by nikhsub1

RE the IHS with AMD vs. Intel; Intel used to have poor IHS to core mating, back in the Northwood days. I experienced a 2.6 which after removing the IHS I lost 9C, with 3 other Northy's that I popped the lid I lost about 3C. Intel today has a MUCH better way of bonding the IHS to the core and it is virtually impossible to remove the IHS from an Intel CPU today. I fear from what I am hearing that AMD has garbage IHS to core bond, until they fix this issue it would be best to pop the lid, this I am sure of.
No, I suggest you go read the thread, this is NOT about popping IHS's. The AMD ihs to core integrity is SHIT, no two ways about it. And, you obviously have not been reading or you would KNOW that Intel IHS's are almost impossible to take off

I can accept that the AMD bonding is not consistant enough for repeated WB testing (@5 mounts per WB).
Beyond that you have established that Northwood bonding was shit, but not that the current Intel system is superior in any way to the AMD system for normal or extreme use. AMD's TIM may be superior to epoxy. (Didn't Intels overheating heating problems begin with it's use?) Some may consider the inability to remove Intels IHS a fatal flaw.
If AMD's joint broke down in the first few remounts you would have a point, but I haven't experienced any problems with either of mine.

edit: "It changes from CPU to CPU, and one IHS capped CPU will appear to favor one waterblock, while the exact sameCPU type from the same manufacturing batch will favor a different waterblock." Now this can indicate a problem, need American, union workers to correct!!!

[Marci]

Or have they gone to solder/epoxy as intel has?

Some black crap - 10 secs with a craftknife blade and it's off... no difficulty particularly - unless you push in too deep and swipe off a few resistors etc... LX tape on the blade prevents that tho...

I've been overclocking since 1996. If I'm not an enthusiast... I don't know who is. Yet I REFUSE to take a knife to my $600 X2 4400+ processor. It ISN'T going to happen, and I am quite sure I am not alone here.

k - so you KNOW the power of your cooling system, yeah? So, imagine if in 6 months time you decided to buy a second x2 4400+, and swapped em straight over, but for some reason the new chip is running 10 deg hotter than the old... AMD won't replace as there's no fault - the chip works, just does so slightly hot - but there's nothing that defines what temp the cpu should be running at according to manufacturer, as long as it's below xx deg C... so nothing to go against in the argument that you want your CPU replacing cos it runs 10 deg hotter than another... you're stuck with that CPU. That's what folks are having to do here. They move from one CPU to another, that should give them an expected marginal temp increase.... yet they're seeing a RIDICULOUS temp increase for no apparent reason. S'not in the mountings. I've had em brought in to the store for me to try and sort, and only conclusion is to remove IHS as the chip isn't faulty per-se... or deal with the fact that your PA120.3, Storm G4, & Laing D5 with Panaflo M1A's can't keep the only thing in your loop within 15 deg of ambient at stock under load when in fact it should be more than easily capable. So, a £400 chip vs a £300 cooling system. And you're losing all the benefits of that cooling system cos of some crappy bit of tin they've badly gooped onto the die. No RMA Option on the kit - it ain't the kit's fault either.

For some removing IHS is a necessity. You're lucky that you haven't had a bad chip that has resulted in the NEED to remove the IHS.

Those who've experienced such will likely remove the IHS from every CPU they buy thereafter just to remove the ballache of a chance that you mount it all up and you've got ANOTHER duff one...

[Cathar]

The problem I have with IHS's, at least from the point of view of enthusiast overclocks is this.

There have been a number of cases reported in forums where an IHS capped CPU will "favor" one waterblock that ranks worse, while the supposedly better waterblock will both perform worse temperature and achieve a lower overclock. After many suggestions and remounts, this was the conclusion that was reached.

Then said users changed the CPU to another CPU of the exact same type, and the stories are reversed. "Worse ranked" waterblock sees much higher temperatures and a much worse overclock.

What is evident here is that subtleties in the IHS manufacture and waterblock geometry are at play. The CPU die to IHS TIM joint is NOT invariable and cannot ever be assumed to be so, and worse, cannot even be assumed to be consistent on a per cpu type or even on a per waterblock scenario. It changes from CPU to CPU, and one IHS capped CPU will appear to favor one waterblock, while the exact sameCPU type from the same manufacturing batch will favor a different waterblock.

I've said it many times before, but I'll repeat it again. If we're looking to quantify the cooling effect of a generic IHS scenario, then we HAVE TO remove the variability of the CPU Die -> IHS joint, which means machining a heat die that looks just like an IHS capped CPU, but is a solid one-metal-no-join piece design.

For those struggling to picture what I mean, imagine something like a 13x13mm (or whatever sized) copper heat die with a "mushroom" IHS lid on it, but all one solid piece. In fact the word "mushroom" pretty much exactly describes the sort of one-piece thing I'm talking about. Heat energy is applied at the mushroom stalk, the temperature of the die is taken from the center of the stalk just below where the IHS "head" starts to fan out. Heck, groove the IHS head and stick a TC in there too, ala Intel TTV style, and then we can validate that the relationship between IHS surface temp and stem temp is consistent.

In this manner the variability of the CPU die -> IHS joint is totally removed and we now have a fixed invariable model that is not subject to TIM joint degradation or block-IHS-TIM-die geometry variations.

Of course we can argue all day that "this is not exactly what an IHS capped CPU looks like", but what are we going to do? Measure and present results based upon a device with what many have observed to have huge variations? The best we can do is to model/measure against an invariable model and the day that the CPU makers get their act together and provide an invariable CPU die -> IHS interface, then it'll all make sense, and certainly a lot more sense than measuring performance based upon a variable laden model where if we start to tune just for that specific model we really don't know what variable we're actually tuning for and which way the effects of that variable are swinging in terms of waterblock->IHS->die geomterical interaction.

Keep it simple. Keep it consistent. Don't play the variable game, and don't develop waterblocks around unquantified variables.

That's what I'm proposing.

[GlassMan]

Got curious about this statement, from athe Apogee page

It should be added that under certain circumstances, the Storm water-block may perform better than the Apogee water-block. We cite for example earlier generations AMD Athlon XP, MP and Duron processors where the die size is smaller in surface area (100 to 140mm2) than current microprocessors. In such instances, the difference in temperature was found to be 1.4°C at 100 Watts, and at the maximum flow rate allowed by our test equipment (about 3.3 GPM for Apogee, and 2 GPM for Storm). Such test were conducted using the alternate testing procedure described in the link below.

The Storm (@2g/m) is superior to the Apogee (@3.3 g/m) with any single core cpu made the last few years, and the next few years to come. I guess I had better toss my 114mm San Diego and 14Xmm Newcastle as they are "earlier generation", along with my Storm.
Gotta love market speak.

I don't understand how the Apogee can cool the center of the IHS better than the Storm, single or dual, as the cooling power is concentrated there. If the diameter of the jets matrix on a Storm is less than 21.7mm (apprx. diagonal of X2 2Mg cache) I can see how the Apogee can outperform the Storm on a dual core as far as overclocking.
Can't wait for more data to see if the results hold up.

[Cathar]

Oh, and I tried to quantify the MCW55 on my video card GPU, but lack of an adequate temperature resolution on the card prevented me from gathering results good enough for me to make any conclusive statements about it. What was evident to me though was that it was performing roughly on par with an old Hydra prototype which was assessed on my CPU testbed to be around 0.5-1.0C worse than old original all-copper White Water at ~110W heat load. Still, such results are not conclusive in any shape or fashion and I have deliberately held off making any comments about the MCW55, other than to suggest in public that it is certainly a good performer. No GPU block has ever enabled a higher GPU overclock than the old Hydra prototype and the MCW55 was certainly the closest thing I've seen yet to it. Still, the old Hydra prototype is now WW beater, let along a Storm equaller. Take that for what it's worth, which in my opinion is worth very little and such an observation should be taken with a very small grain of salt. I have next to no faith in the finality of that performance assessment of the MCW55 other than to say "it seems pretty good for GPU's".

Am presently trying to get a suitable CPU mounting bracket for the MCW55 machined up so I can quantify it directly on my CPU testbeds. One of my machinist's CNC mill's broke down though and so I have next to zero machine time available prior to Christmas.

[Roscal]

Happy that Cathar talk about that, it was the same idea as mine to make my proper die with IHS but without TIM to avoid assembly, never realized because no time... Not difficult to mill at all, some care should be take to avoid conduction secondary paths. I would to use a MOSFET because of the small size and capable to dissipate a lot of power easily and easy to control, power resistors or cartbridge are generally too big for a small and light die like that (no need to heat 500 gr of copper, too long and useless...). TIM die/IHS is only a gap in Rth, its thickness is too small to change flux repartition, so we could pull out this element and get a solid one piece die with a flat surface above. IHS and die center would be instrumented with very small TC using EDM holes (diam. <0.3mm). This kind of die would be much better than bare die for sure, nearer to reality in terms of flux spreading (always different with any WB !)

In french on attached pic but you'll understand... I think Cathar's idea is like mine if I understood well.

[Cathar]

Yep, that's exactly it Roscal. Easy to machine.

I've actually been saying this off and on for quite a while now. Seems no one took notice. I myself have been working towards getting one made up, but always seemed to have more pressing matters with my real job, but lately with all this IHS waffle I've been becoming increasingly more motivated to do so.

[Roscal]

Problem is to know the die area below IHS, I put 12x12mm at one moment, but now dies are larger and often change with generations. Make a die every year is a pain... I don't know really if differences between 12x12 and 16x12 for example will be great, not sure, because IHS acts as a good smoother... Need tests and data, or numerical studies to get a first approach, I'll make tests with Fluent one day, not difficult to model at all...

[Orkan]

Originally Posted by nikhsub1

Because when an IHS is on for shit, each mount will further degrade IHS to core integrity, c'mon i don't claim to be 1/10th as knowledgeable as Bill, Cathar, pH, Lee, Les and a host of others, but surely this fact should be common sense.

out of the 800 or so computers I've sold through my retail pc store in the last year.... All have had AMD processors. At least half have ben Athlon64's with IHS on them.

I've only had two of them report extremely abnormal temps. Of those 2, both cases were caused by faulty motherboards.

I fail to believe that re-mounting on the same cpu will degrade the IHS weld to the core. It is either on right, or not on right. It doesn't magically start coming off by itself. ... or at least I've never heard of it happening.

[Cathar]

CPU die sizes, including the dual-core dies, seem to be mainly sitting between 140-220mm^2, with the AMD dies typically being the most oblong, and the Intel dies being the squarest, although that has changed somewhat with some of the dual-core Intel dies. The most oblong long:short edge ratio seems to be no higher than 1.8:1 to date.

So perhaps a ~180mm^2 die size, with a long:short edged ratio of 1.4:1 would be a suitable middle ground? A 16.0 x 11.5mm die size shape? Just throwing a suggestion out there. Everyone's going to have different opinions on what would be most representative, or what would be the most acceptable "middle ground" unless testers are prepared to provide results on multiple IHS testbeds.

[BillA]

no
it is improper to characterize all CPU/IHS TIM joints as being intrinsically variable to a huge extent
that some may degrade so over time and use has nothing to do with testing (don't use old shit)
that some may be inconsistantally mfgd is another separate issue (don't buy cheap shit)

Cathar, take your entire post above and read it in the light of a consistant TTV CPU/IHS TIM joint being a fact
there is nothing to your post, it is ALL totally predicated on variable TIM joint performance
remove that variability and all that's required is learning what the new numbers signify

I have cross-tested multiple TTVs, and tested them over time; they are fine tools
-> what is perhaps not known/being applied is an appropriate correction factor
nothing wrong with a TTV

the real difficulty is that TTVs are not available

anything positive ?
there DO seem to be (today) CPUs not having IHS issues
"Keep it simple."
we agree, test the actual configuration where possible; and since there ARE CPUs w/o an IHS problem . . . .
but this still leaves the quantification of heat unresolved if using a CPU source

". . . which means machining a heat die that looks just like an IHS capped CPU, but is a solid one-metal-no-join piece design."
and this will replicate the heat flux through the TIM joint, and the subsequent lateral spreading through the IHS ?
Roscal says so, I have no good basis to object
where is the DIE TEMP to be measured, and how ? (I missed this in your post)
Roscal did make a suggestion, but
- how do you establish the correspondence of this measured slug temp with a CPU temp ? where the temp is taken and its value are irrelevant, the correlation is key
there are some assumptions here, as did I with my old heat die; I defined it so
how many today would accept that ?

junk the hat, work on valid CPU specific correction factors for a simple post
NB if you want to assess dual core cooling you will need a dual core source (or do junk testing)

-> how is the die face to be maintained ?

do you know what the TTV has that no die will ever have ?
repeatability, lesser absolute performance but a greatly reduced range

[BillA]

Orkan
many mountings or severe thermal cycling will do it
outside of the scope of 'normal use'

Marci's experience is different due to his customers

[Cathar]

Bill, sorry, but I'm going to have to say it.

I really don't understand your steadfast defence of a testbed where the TIM layer is not quantified. Really. Please. You don't know the die temp on the TTV, so you cannot EVER conclusively say that it is invariable now can you? Why? Because you don't really know.

Truly, I find this head-in-the-sand approach from you most out of character and disappointing.

There. I said it. I just had to get that off my chest. I have never ever witnessed ANY person who claims to hold to a scientific testing methodology and then blatantly dismiss what is a potentially variable, especially in light of the admitted "bad data" that has been observed, and then say "sorry - no - I don't care - it's invariable".

Seriously, please. Pleading for ignorance now? Why? I cannot understand this mentality from you. It is so against everything you've ever stood for in the last 5 years.

[Cathar]

Originally Posted by unregistered

NB if you want to assess dual core cooling you will need a dual core source (or do junk testing)

Can't have it both ways Bill. Dual core CPU's are just a single piece of silicon and look just like a single CPU silicon die externally. Heck, some of the newer dual core silicon dies are even smaller than the older single core CPU silicon dies and present more localised and compact thermal footprint.

While championing the TTV for dual cores, you're also putting forwards a case that a single middle-of-IHS case-temp is suitable for all scenarios.

Can't have it both way.

I find this defense of the TTV model utterly and totally incomprehensible in light of the admitted and unexplained bad data. In scientific terms, the TTV is a theoretical model in which observed phenomena cannot be explained. Either find the explanation or the model is as invalid as any aspersions you care to lay at any other testbed's feet.

What will happen Bill if independent testers start to find results that do not agree with the TTV? Will you then engage in tearing down every independent tester that does not usa a TTV?

[Roscal]

Bill > I didn't say to take only die T° at a certain point (copper isn't silicon, processor get numerous hot spots, flux has a very complicated shape and never "flat" like a bare die, thermal probe in processor die could be near an edge or elsewhere). If I had a my die done, I'll take several T° as well the IHS internal T° to get a global view, but IHS center T° above core is normally enough to characterize a system thermal resistance (with a groove on it like Intel TTV or with a tiny hole to fit TC/RTD just above center die at 0.2-0.3mm from IHS surface with my version), die T° reacts as IHS center do. Absolute T° in copper die won't be never the same as a processor so we can't say if I got 2°C difference with my die between X and Y, I'll have 2°C better on my processor between X and Y, this is not true. Die T° is just to complete data and see if relations are linear between 2 different coolers, we could have a better view of how an central impingement will affect IHS T° and core T° in comparison of a simple WB for example, flux spreading, etc. We can imagine 5 thermal probes in IHS, one for center and one in each quadrant, why not..

[Orkan]

round and round we go.

Let me ask this simply:
How does varying levels of heat, change the ability of a waterblock to remove said heat?

So from one cpu to the next, there are varying levels of heat being transferred through the IHS. So what. Every single person that buys these blocks knows that someone else with the exact same setup, may have cooler, or higher temps based on the fact their CPU's may put out less or more heat.

The heat being trasferred to the block by the cpu being higher or lower does NOT affect the ability of the waterblock to remove that heat.

The amount of talking and lack of doing astonishes me. Ok, so you say you can't re-mount a waterblock to the same cpu because the IHS is changing its contact every time you do. The law of greater numbers will take over when you average out, and give you solid numbers either way. (solid enough for me and 90% of the community anyway)

You have 2 waterblocks. You want to compare them. You say if you use the same processor/comptuter setup to test them, the IHS will be different every time you re-mount. So mount it five times, alternating the block you use. ... so the variations will be as close as you can get. Then do the same thing on FOUR other computers.

I get the distinct feeling that everyone just keeps talking, making things more complex and more complex until no one knows at all what anyone else is talking about... but they sure did talk alot.

Bottom line: - as a consumer
Who is going to figure out which block performs better?
How are they going to figure it out?

Not that it would really matter... as demonstrated by this thread. No matter who did the testing or how they did it... half of you would believe them, and the other half would not.

Round and round we go. Someone pass the pepsi.

[nikhsub1]

LMAO @ Orkan. It seems as if this whole discussion is upsetting you Orkan. This is how perhaps progress can be made in the world of testing WB's. Or not. Good dialogue for sure. Let me explain again, to you; the IHS issue at least with AMD and older northwood Intel CPU's. The IHS is affixed to the PCB of the chip, not to the core itself. You slide a blade round the IHS on an amd and whammo! the IHS will come off. This was also the case with the NW's of which I've owned many and have seen DRASTIC irregularities in temps between like CPU's with IHS on, however, pop it off and each CPU is well within what one would consider a 'normal' margin, ie they thermally behave very similar at similar speed and voltage. How could this possibly be?

[pauldenton]

Originally Posted by nikhsub1

FWIW, I tried to get a soldered/epoxy'd ihs off of an Intel cpu, to no success. I stuck in in a 400 degree oven for an hour, froze it overnight, soaked it in googone, nothing worked. Believe it or not, the CPU still runs to this day.

[Annirak]

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?

[Albigger]

where is the DIE TEMP to be measured, and how ? (I missed this in your post)

For those struggling to picture what I mean, imagine something like a 13x13mm (or whatever sized) copper heat die with a "mushroom" IHS lid on it, but all one solid piece. In fact the word "mushroom" pretty much exactly describes the sort of one-piece thing I'm talking about. Heat energy is applied at the mushroom stalk, the temperature of the die is taken from the center of the stalk just below where the IHS "head" starts to fan out. Heck, groove the IHS head and stick a TC in there too, ala Intel TTV style, and then we can validate that the relationship between IHS surface temp and stem temp is consistent.

Of course as said this has no correlation to CPU die temp, or some such correlation would have to be developed (if of interest).

do you know what the TTV has that no die will ever have ?
repeatability, lesser absolute performance but a greatly reduced range

How is a TTV more repeatable than a heat die?

[pauldenton]

Originally Posted by unregistered

no
it is improper to characterize all CPU/IHS TIM joints as being intrinsically variable to a huge extent
that some may degrade so over time and use has nothing to do with testing (don't use old shit)

but how is anyone to produce comprable results for multiple blocks over time without using the same "old" chip......

[BillA]

Cathar
everything can be considered variable, we accept that
it is the degree of variation that is in question
I would not use an AMD CPU because of what I have heard about the IHS, I have no personal experience however
I have not heard of IHS related problems with current Intel products, nor in asking do I hear of them
so I do NOT assume AMD and Intel have the SAME CPU IHS problems

the TTVs use a TC so resolution is limited to 0.1°C, cross ckg TTVs indicated no differences that I could measure
are they all the same; forever ? - no, nothing is

Cathar, I have no devotion to TTVs, I will probably never have one; but they are a repeatable heat source
if the TTV numbers are wrong, they need a correction factor (as Intel provides for specific CPUs)
if the Swiftech numbers are wrong, they need an (appropriate) correction factor

I repeat, the TTV is a fine tool; the data's interpretation may be/is the problem
baby and bathwater issue
the TTV is only a tool, and 'produces' test results; a TTV does no cooling
as Intel says, confirm the results (Swiftech seems to have done so on a CPU)
-> a conflict between TTV and CPU results ?
the CPU every time, what else ? (the TTV is not a cooler)

get real Cathar, why would I "tear down" a tester for something they cannot get ?

I see the latest posts and now we have people believing that IHS and silicon temps are independent ?
ah, progress

[BillA]

Originally Posted by Roscal

We see well the limits of testing here. Swiftech made several new dozen of measurements on different systems with Apogee and Storm, data are valid (some will be made on a true processor very soon to get more data) and finally, they got opposite results according to the testbeds. What to conclude then? Yes it's a good block but is it the best? Not ! What best mean? on which system? With which others parts? Etc. Swiftech want principally to reduce costs manufacturing without reduce performances too much, they suceeded a priori and they could release good blocks at lower price, so more people could enjoy in WC because it's cheaper. It's not a Storm bis, apparence is almost the same because of their process. It's not a crime to keep a design to be their new design reference, or it's like to said "all radiators use the same design", it's the same ridiculous sentence. We need to have a global view of their decision, not only to be stubborn on performances which don't make any interesting differences on most real configurations in typical applications anyway (mounting, paste, load, etc.), some people forget this point...Swiftech is honnest and they say clearly that core geometry will affect efficiency between their 2 top notch WBs, no mystery here. Global and universal statements can't be made on a such complex field like thermal management for processors due to diversity and a lot of people here forget this point too !

Some are playing with dies which are, per definition, far from actual reality and non linear systems like true CPU with an IHS. Robotech will show soon that he got better results with Storm than Apogee on his large naked die. Does it mean Storm is always better? Absolutly not, it's better on his specific testbed, not in all the real cases and perhap's Apogee is always the best in real applications (with multiple processor geometries), who's know. Argue that Storm is the best of the best is true BS, and the same could be applied to any WB obviously, not especially to Storm. It depends of the context and if you aren't be able to understand or extrapolate what differences could be provided between different heated systems, it is because you don't know anything to thermal management, no less no more.... It makes me laugh when I see people on varied forums who are very surprised that Storm could be outperformed a bit by another WB in particular circumstances. No one made an giant & perfect WB testing with all WB worldwide to give an universal answer I believe, so why they need to impose a biased point of view? There's so much mind restrictions that it's impossible to be better for these people, false statement again. It's always the game of who gets the bigger...You look at american forums, you'll see Storm is sainted, you look at european forums, you'll see that Alphacool or others european manufacturer are sainted. Who's right? Let people choose what they want...

Sure, a heated die provides great accuracy if well done, but it ends here and correlations with reality are a real pain and not so easy as some people think. It's easy to see that comparisons between data provided by several people using a die are completly disparate generally ! Who's right? Who's false? None of them again... It depends, that's the universal answer to give you. An IHS has a role in heat flux spreading and almost all actual processors use one, you can't neglect it at all. It's not because a dozen of people pop off the IHS that it's an universal case ! The TTV Swiftech use, in parallel of the BillA's die, is surely nearer from reality than a naked die. IHS acts like a spreader (hot spots are filtered and flux on the IHS top appears to be more constant and a bit less important in terms of power density) and WBs are probably less sensitive to the core dimensions below... If you change the die area or contact, you change its behaviour too because flux are not the same (correlation are complex) and we have a good demonstration here. Is it bad? No. Personnally, I would prefer a controled testbed on real instrumented parts (mobo, processor, etc.) with multiple mounting to ensure consistency like Ph, or I, did. When after months you'll try again to measure again a WB to see if you were correct, and you get same data @+/- 0.1°C you could be happy of that, no need perfs @0.01°C in a world where designs variations are great (I don't say that precision is useless for all measurements, eh). One thing is sure, the more data you'll get from various persons, the more interesting it will be, true data are essential, assumptions or extrapolations remain extrapolations. Swiftech did that using several die systems to get more data, no complaints about that, they don't invent anything.

One key is the downscaling to achieve better convection efficiency thanks to mini/micro structure for example (next generation of Apogee will down scale probably with tinier pins), Storm and others american WB generally are enormous for nothing, 50-70% of their weight/volume is useless (it costs) and we can achieve same results and better integration with WB like my EDM protos if you know them (40x40x10mm only and I could reduce them by a factor 2 if one day I continue this project) or simple WB like MP05 or similar. But external design is a major problem because who want to have a simple small rectangular WB without bling or harmonious curves ? If these esthetics considerations were abandonned by people to keep only efficiency and simplicity, costs and manufacturing processes will be simpler, because Storm needs a lot of milling work for example. Jet impingement is a good technic (the second one with microstructures) but not an ultimate solution and principally because pumps are limited. Some tricks could be made to enhance thermal transfer and Cathar tried some, but you are always dependant of the jet speed and pressure drop related... Remember too that actual WBs are near hitting a effectiveness wall because it become more and more difficult to have a better performer, convection isn't the major factor in thermal transfer now... Apogee has some advantages in comparison of Storm for many circuits (less pressure drop, no clogging, etc.), why don't let it a chance? Not all people are restricted to get an hypothetical 0.5°C less @100W you know...

A lot of time I would say that because it hurts me when I read some headstrong people and their false perceptions. Open your mind a little, it's not a bad thing...

worth quoting as there is a lot of info here

[Cathar]

I'd rather be doing this anyday.