Because you don't know anything about testing methodology, they are not scientific results, just a "melting pot" of home made tests.

The home made tests are OK. It's the statistical analysis that is inaccurate. There should be a standard uncertainty given and then it's evident to the reader that there is a range in recordings.

wow, thanks for that QuietOC. That's just given me a great warm fluffy feeling about SPCR, somewhere I once thought was a forum for friendly discourse. I guess I'll just have to refrain from posting on topics unless I am a, if not the, world leader on a particular subject. Unfortunately this doesn't happen to be Molecular and Evolutionary Developmental Biology Review, so I'll just have to shut my stupid mouth

I remember that somebody has made DIY diamond TIM and what I remember it worked well.

I like to think of heat transfer like water flowing through a pipe. The "pipe" that carries the heat from the high temperature source (CPU) to the low temperature sink (air) is a combination of pieces, like the heat spreader, the TIM and the heatsink. These "pipes" are all in series, and the flow rate is limited by whichever offers the most resistance. Your heatsink may be a "huge water main", offering little resistance, but if the TIM is a "tiny straw", not much heat is going to flow through it.

thanks for that Avalanche, makes more sense. Thinking of it in terms of house insulation helped too - the more you have, the warmer it is inside in winter It's been a long long time since I studied physics

As a further clarification of the equilibrium/steady state argument above, it strikes me that there is a mismatch in how the terms are being used.

Steady state in most of this conversation is being used to mean "the CPU is at a constant load and the temps have stabilized". However, I think Kermit's brother Matt is thinking equilibrium as in both ends of the system have reached the same temperature, which of course happens when we have a finite amount of heat at each end, and the ends are 100$ insulated. But of course in this setup we have an infinite supply of heat at one end (the CPU) and and infinite heat sink at the other end (the air) (infinite being of course a practical assumption, not 100% correct) so in one sense the system never reaches equilibrium (ie. the heat keeps "flowing" forever). However it does reach equilibrium in that the amount of heat flowing and the temps along all points of the system remain constant after a while.

Hope that isn't a presumptuous comment, as I'm sure most realize that, but for the sake of any readers who don't know much about thermal systems I felt it worth explaining.

Maybe not directly scientific results in terms of determining the best solution in an optimal environment, but they might also include the usability factor. Some of these materials are easier use than others after all and some of them might be working better with uneven surfaces than than others.

For the average person, this stuff matters as well and a lab test with a person very experienced in doing this kind of work might not reveal the problems a less experienced person might face with a larger variety of equipment.

wadr, you're confusing "steady state" with "equilibrium". If an equilibrium was reached, the thermal conductivity would indeed be irrelevant for the temperature of those parts that would be in equilibrium. (Take for example a cpu that is turned off and reached a steady state where its temp = air temp. After this equilibrium is reached, no matter what the thermal conductivities are, the cpu temperature will stay equal to the air temp. given the air temp. won't change)

However with working CPU cooling it's not the case. Even after the "steady state" is reached, the cpu has a different temperature than ambient air, so this is not an equilibrium. The heatsink is not in an equilibrium too, it has a thermal gradient. The "closer" to cpu, the hotter.

If we had infinite air circulation (constant ambient air temperature), the cpu temperature would rise to a point determined by the ambient temp, cpu power output and the thermal resistance of the whole heatsink system that transfers the heat to ambient air. The higher the thermal resistance, the higher will the cpu temp climb after it's turned on to reach the "steady state". If there was no heatsink, it would climb quite high, but eventually would stabilize (think of a stove/kitchen hob)

So in short, what you said is close, but does not apply to cooling a cpu that is turned on, because even after the temperatures stabilize to a steady state, there is no equilibrium between the cpu, heatsink and air temperatures, they're different.

disagree.. in my thermodynamics course i think this was called 'dynamic equilibrium' and is a type of steady state. the commonly quoted example is bucket with hole in the bottom and water pouring in at the same rate as it leaks out - though the system is dynamic, the rate of inputs equal to the rate of outputs so that some property, in this case the water level, is constant in time. the analogy in the case of heatsink would be rate of heat in and rate of heat dissipated equal, and the constant property in this case would be temperature. it is irrelevant that the temperature gradient is not constant throughout the heatsink (spatially), it is called steady state if the temperature gradient is constant temporally.
compare the case of a heatsink , cpu off, which has stabilised to air temperature..this is also steady state but called static equilibrium.
see e.g. http://en.wikipedia.org/wiki/Dynamic_equilibrium

After my posts a fortnight ago I decided to email Electrospell to ask them directly about their product.



Haven't received a reply.

I recall being laughed at by a certain Mike C when I asked if Diamond paste was possible for cheap


EDIT


Okay I was rambling about a diamond heatsink base. Tomato, tomatoe.

I agree. I was simply talking about an equilibrium of equal temperatures, not power in/outputs. As I said, equilibrium of temperatures don't depend on heat resistance, but the equilibrium of power transfers, in- and outputs do. To rephrase my last post, if there were different materials with different heat resistances involved, a different equilibrium of power in- and outputs would be reached.

FYI, for those who want to try some...

Innovation Cooling IC Diamond 7 TIM Giveaway

For those who lives in U.S. and in Canada unfortunately... to quote Kummeli in this situation: "The answer is: Canada!" *sighs* Maybe one day we, in the old world can also help in these kinds of things... Free tim is always good...

For those that likes their raw data



For those that likes their bell curves




Bell Curve Notes

About half the data is reported in round numbers and approximately 50% of the total numbers were fractional numbers, so to include all numbers in the set I rounded the fractional numbers to the nearest ½ degree. This had a minimum impact on the overall numbers, for instance the mean dropped less than 2/100th’s of a degree.

Notes: IC Sampling Vs. Individual Tests

Innovation Cooling elected to use this more or less unique method to introduce our products as the review cycle runs like molasses for thermal compounds, 10 -12 for ICD in the last 2 years with many comparisons already obsoleted due to new product cycles.

Hardware reviews serve an important function along with observations of user experiences allow individual users to either consciously or unconsciously mentally benchmark results. Our problem was there were not enough reviews to to make comparisons on as compound comparisons are notoriously tedious vs. heat sink or other hardware.

Single tests , individual or even those done by Innovation Cooling are anecdotal in nature subject to limitations of methodology. While most pursue the most rigorous test procedure possible they still encounter fluctuations of several degrees C between tests/reviews.

Why does every test come to a different conclusion? The problem is that their sample size = 1.

Even collecting multiple readings the cluster size is = 1. An individual can collect all the data readings off one system, and will still have almost no statistical power (In statistics this is known as "Intra-Sample Cluster Correlation")because the test set up is dominated by methodology. This is a problem not only in individual paste reviews, but in other hardware reviews, heat sinks, etc. as well.

In the final analysis methodology ends up defining the final placement of all compounds- All test methodologies fail to take into account things that have a major impact on paste performance. For example the mounting system along with mechanical contact between IHS and sink as evidenced with our independent contact/pressure testing. Variability was very high on the contact results with perhaps 1 in 10 having any thing near what you might call full contact, even on those with lapped components.

In considering pressure related to mounting hardware some pastes perform relatively better under poor mounting, others perform relatively better under good mounting (viscous ones such as ICD). Considering ICD - people that had poor results with ICD had very poor mounting. Once they improved that mounting, ICD did considerably better. Of course, so did their old paste. But ICD improvement >> old paste improvement. Generally, this resulted in ICD>old.

In summary, sample size = 1 tells little. . Sample size matters!

ICD has been extensively tested by 391 independent users in 11 forum groups data that is compiled with real world, real users test results

I can attest to IC7's effectiveness


Unfortunately, I don't use it anymore because it's too thick, and gets hard after a while.

Well everybody has their own preference and I can not argue that

But there is methods to madness

Spec from OEM's over 90% bulk loadings, thick is for reliability, - Sets up to crayon like consistency but still pliable is by design not by accident, it will not pump out(paste failure) for the simple reason is you can not pump a solid. Removal dampen with acetone wait a few second for the paste to absorb and it easily wipes off

Pump out is the principle cause of compound failure - tons of industry documentation on the subject

Of course if you change you paste every 100 hours or so you won't have this problem

http://www.maximumpc.com/forums/viewtop ... c&start=48

I do have one more update..
my locale has intense physics, its the weather. I forget the year round cycles of my pc. Recently a hurricane came through on the shoreline, for maine, its like hot and warm at the same time, a dewpoint function unknown to man, and hho gas building in old subarus. I am in an a/c'd room with the pc, but I must admit there was something tougher in the elongated warmth the pc gets at these times, it seemed to go back to normal after the storms, and hardly responds to chunks of hurricane squalls still passing through. I do not know what this means, or if I am giving credit in the wrong place. It is some of the best I have used, I think it may need to be as tough as somebodies previous comment about hardening. (As some may remeber p4 oem sinks, the hard paste) It has been a great replacment, thanks for sample. I personally will seek it as a habit.