So MX4 isnt as good as AS5?

[scrambler]

^^^I'm guessing you bought one of those massive 22g tubes like I bought. It's not really up there anymore but its still only a few degrees off current pastes. I'll go to MX4 when this runs out. $18 for a 22g tube

I did actually! Was super cheap and I had my doubts it would be good, but it surprised me. Only paste I have ever used so far. I did my first paste with it. I'll always remember that.

 

[mjw21a]

My first was the pre applied pads, then Arctic Silver 3, then Shin Etsu G751, then Artic Silver 5, then I moved to the AS Ceramique and have been using it ever since.....

 

[xander89]

AS% at more than one place is not as good as newer pastes. Even taking into acount for the break in period.

And that is too much paste. This is how my paste looked after 8 months on a rebuild. And that is just my opinion. And I use the blob method.

What is too much paste? I use a blob the size of a small pea/ grain of rice. Find that easily enough to get a fine layer over the ISH.

Also no worries mj just a but tetchy atm that all. Sorry for flipping out like mr panda.

My method is one that I Prefered while using as5. But diamond pastes/ thicker ones it just doesn't work for. I understand that. But I feel for as5 it's a viable method of application.

I'll probably have to switch if up when my mx4 comes. Sounds like its a bit peanut buttery, which sucks ***!!! Lol

 

[bluezero5]

I consider that too little.

 

[xander89]

tbh the less the better, as long as you have contact.

 

[Woomack]

For me MX2, MX4, STG2 or cheaper Gelid are better for gfx than AS5. MX4 = STG2 for me and I usually buy what they have on stock. Both are a bit better than cheaper version of Gelid but Gelid acts better under sub zero cooling. Price for all above is about the same.

 

[bluezero5]

tbh the less the better, as long as you have contact.

That is a true statement.
however on the above, it is clear the full CPU is not having full contact with the heatsink, hence you have already without paste. the surface of the chip is 'slightly convex', as such, to me, the tim is a way to help solve that by filling any possible gaps to improve contact.

without TIM inbetween, the chips's sides which can dissipate a good percentage of heat is not in good contact with the heatsink. meaning, temperature difference.

i have done hours of testing previously, and the rule i discover is.

- keep entire chip with as thin as possible layer, is the best.

 

[xander89]

That is a true statement.
however on the above, it is clear the full CPU is not having full contact with the heatsink, hence you have already without paste. the surface of the chip is 'slightly convex', as such, to me, the tim is a way to help solve that by filling any possible gaps to improve contact.

without TIM inbetween, the chips's sides which can dissipate a good percentage of heat is not in good contact with the heatsink. meaning, temperature difference.

i have done hours of testing previously, and the rule i discover is.

- keep entire chip with as thin as possible layer, is the best.

this is kind of what the principle of spread it with either a credit card/cling film on the finger.

To be frank i think there is so little difference between the methods, the temp difference could be explained but a simple remount.

 

[mjw21a]

The whole heat spreader surface doesn't need to be covered though. Just the portion of the heat spreader above the CPU die itself.

Remember that the heat spreader doesn't actually do much to spread the heat, but is more to prevent the core being crushed

 

[EarthDog]

Integrated Heat Spreader has little to do with heat dissipation?

 

[mjw21a]

I remember tests regarding it years back. The majority of heat from a CPU die goes straight through the spreader without actually spreading it out, meaning the IHS actually had more to do with preventing the core being damaged during heatsink installation than cooling itself.

After all, you'll generally get better cooling without any heat spreader, although this is primarily to do with having two fewer layers between the core and the heatsink (IGP + IGP grease/solder)

 

[RGE]

The whole heat spreader surface doesn't need to be covered though. Just the portion of the heat spreader above the CPU die itself.

Remember that the heat spreader doesn't actually do much to spread the heat, but is more to prevent the core being crushed

Intel engineers disagree with you. There are several white papers on the subject. They called it a heat spreader because that is its primary function. The effectiveness of it, is dependent on tim1 vs available tim2.

EDIT: people forget to add surface area into the calculation. IF tim1 (IHS to die) resistance = tim2 (HS to IHS) resistance, then IHS does not lower tj. IF surface area of IHS is not larger than die, then IHS does not lower tj. BUT, if tim1 resistance is several times lower than tim2 resistance, and if surface area is made larger at a faster heat conductance prior to having to go through user tim interface at 4 w/mk (but now helped with larger surface area), then the IHS will decrease overall thermal resistance and lower tj. In other words, with enough of a decrease in thermal resistance of tim1 vs tim2, and enough increase in surface area, at some point an IHS will decrease tj vs no IHS. The IHS increases the "effective" size of the die by more than just the surface area increase to IHS, since it also spreads heat out more uniformly. The same principle holds true for using a heatsink. Why not remove the extra layer of tim2 and the heatsink and just blow air on the IHS, because you are removing a layer. The reason is because you want to spread heat to those fins at 400 w/mk and dramatically increase surface area, before trying to use air at .026 w/mk to remove heat. Just like solder at 87 w/mk then copper IHS 400w/m, spreads heats many times faster to a much larger effective surface area of IHS, before having to make it through user tim at 4 w/mk.

Back in temp testing in Realtemp thread, trying to figure out tjmax, using calibrated thermocouples, temps on bare die are nonuniform. After going through intels solder die attach at 87 w/mk then copper at 400w/mk, the temps on IHS are much more uniform, less than 1C from center of IHS to edge. There are intel white papers showing same, linked in Realtemp thread a few years ago. The more of IHS you cover with tim2 the better.

But whether intel Heatspreader decreases tj or increases it, depends on tim1 (between IHS/die) being several x less resistance than tim2. Solder at 87 w/mk + IHS will decrease tj. If you remove a solder 87w/mk IHS (resistance c/w of .0098) and replace with user tim with 10x lower bulk thermal conductivity, higher contact resistance you will increase not decrease tj. If you remove IHS, and solder on your waterblock designed for size of die, and make bottom of your die the IHS, then you can decrease tj further since replacing tim1 with same specs.

Here is link from an intel white paper, dont have time to find white papers at second, need to go to work.

http://www.intel.com/support/processors/pentium/sb/cs-011043.htm

How does the heat spreader improve package thermal performance?
Since the Pentium® Processor requires an external heat sink in order to maintain the junction and case temperatures below the acceptable levels, the main contributors to the total junction to ambient thermal resistance are junction to case (ThetaJC), case to heat sink (ThetaCS), and heat sink to ambient (ThetaSA) thermal resistance's. ThetaJC is mainly a function of internal construction of the package and packaging material thermal properties such as the die size, die attach and ceramic thermal conductivity. ThetaCS is a function of the thickness and thermal properties of the interface material between the package and heat sink, package and heat sink flatness and surface finish and effective heat transfer area between the package and the heat sink . ThetaSA is a function of heat sink design and the airflow type and rate.
Using a heat spreader in the package lowers the overall thermal resistance in two ways:
1) It increases the effective heat transfer area between the package and the heat sink and as a result lowers ThetaCS. The actual reduction in ThetaCA depends on the magnitude of ThetaCS without a heat spreader. The larger a value of ThetaCS without using a heat spreader, the larger will be the reduction in the value of JA if a heat spreader is used.

2) A heat spreader may also improve the heat sink thermal performance by increasing the effective heat transfer area in the heat sink and making the fins away from the die more effective.

 

[freeagent]

Honestly, I only use as5 because thats all I can get locally

that and ceramique.. My fave was ICD7, man that stuff was wicked. The stuff that came with my Noctua was pretty decent.. better then the thermalright stuff.. I did use toothpast once in a pinch.. it actually worked ok until it dried out

 

[bluezero5]

+1 to RGE

 

[Conumdrum]

Yea, RGE is right. My pics of the application of TIM shows that I use much less and still get great temps. Could of been a bit better application though, could be the IHS shape etc.

It shows how thin the layer was and the thinner the better for heat transfer.

 

[GeneO]

tbh the less the better, as long as you have contact.

That is it. It depends on the surface of your heat-sink. If it is coarse or not flat, you will need more. The above picture of the copper plate looks very polished and probably doesn't need as much as others. So I don;t think less is always better.

I find that if I cover the whole area of the IHS, and rge is on the money.

 

[mjw21a]

I expect my Noctua to be durn near perfect.... It better be for the price

 

[Conumdrum]

Do the glass test. Kechup on a glass plate. Push hard, look at the bottom of the glass. Works for the CPU too.

Careful, we want a bit of convex on the cooler. Looking at my pics, see how thin it is on the IHS and waterblock? Great uber thin contact where it matters.

 

[720x770]

You people aren't professionals. You keep passing along inaccuracies. There is no such thing as too much thermal paste, since once the heatsink makes contact, it spreads all the paste around and off to the sides. so if you add a lot of paste, all you'll get is a mess on the side and the same thickness layer of paste on the CPU. The thing that most determines the thickness of your paste is the tiny gap between your CPU/heatsink. Too little thermal paste is worse, while too much thermal paste is harmless. AS5 is the exception since it's capacitive, so you don't want to make a mess or it's dangerous for your components. But it's not a paste I would ever recommend anyways.

Of course you don't want to make a huge mess anyways or waste paste, but a pea sized amount is definitely too little for most processors. From my professional experience, the 'X' method works well on CPU's. My GPU is more rectangular, so the 'line' method works well length wise. These both ensure optimal coverage.

You don't want to just have coverage over the center of the processor, you want coverage over the whole processor heat spreader, increasing the area of contact thereby increasing heat dissipation.

Now when it comes to pastes, AS5 is capacitive, meaning it can connect and fry circuits if it touches them. It also doesn't spread very well, and eventually hardens to become a powder, it can even essentially glue your CPU to your heatsink.

I've personally used MX-4 paste and it's some of the best stuff out there. It spreads well, it's an actual thermal grease rather than a thermal 'puddy'. It will stay in grease form, meaning you could take it off of a heatsink years later and it will have basically the same consistency as the day you put it on. It won't glue your heatsink and CPU together, making it effortless to take off a heatsink if you ever need to. It's guaranteed for 8 years at least, which you'll probably get a new PC before then anyways. Zero curing time. It's not capacitive which means you could spill this stuff anywhere inside your PC and it won't harm anything. It's really good at keeping temps down, your temps will basically be as low as they're ever going to get compared to other pastes. even if another paste had a 1c difference that would be negligible. I have a huge syringe of MX-4 I bought for $12, enough to do more than a dozen processors and GPU's, so it's pretty cheap too. Hands down, I would personally consider it the best paste on the market, and since it has every positive feature anyone could want in a paste, it's the only paste anyone should bother with whether you're an expert or a novice.

AS5 is for misguided wannabe elitist fanboys (noobs) that don't know any better.

 

[bluezero5]

You people aren't professionals. You keep passing along inaccuracies. There is no such thing as too much thermal paste, since once the heatsink makes contact, it spreads all the paste around and off to the sides. so if you add a lot of paste, all you'll get is a mess on the side and the same thickness layer of paste on the CPU. The thing that most determines the thickness of your paste is the tiny gap between your CPU/heatsink. Too little thermal paste is worse, while too much thermal paste is harmless.

+1 for that.

I have tested 60+ mounts varying amount of thermal paste.
and you are ABSOLUTELY right.

there's only too little, there's no issue found with too much.
as you said, your mount will squeeze out the excess easily.

and you totally want to have your 'entire heat dissipator on the CPU covered, as you want MAX exposure with the heatsink connecting to it.