Arctic Cooling MX-3 and MX-4

Intro

This is the fourth installment of many of the Skinnee Labs TIM Comparison 2011.  For most of the installments, results will be released in sets of two or three TIMs roughly every two to three weeks but today we have two and a third TIMs.

Arctic Cooling makes one of the greatest TIMs of all time, MX-2. It’s great because of its performance, usability, availability, and pricing.  Despite being an ‘old’ TIM it’s still the yardstick (and a good one) by which other pastes are compared against.  As time has passed, MX-2 is no longer the best performing TIM, but it’s still really good. In our opinion, if MX-2 could have a sequel that matches MX-2′s usability, availability, and pricing while increasing performance, it would be just an amazing TIM.  MX-3 and MX-4 are the sequels, do they live up to it?

The short answer is, no.  Neither match MX-2 in price, MX-3 has actually been EOL’d (there goes availability), and MX-3, as we mentioned in our old review, requires an abnormally large amount of paste to be applied each time (there goes usability).  What about the availability and usability of MX-4?  And the performance of both of them on the new testbed?  We’ll try to answer that.

But there’s a big complication.  MX-3 has at least two different variants on the market.  Over time I collect pastes to test and for this review I had one syringe of MX-3 left from our first test of it (this syringe was purchased from the first production batch of MX-3 to reach the United States).  I knew it wouldn’t be enough to get 15 mounts done, so I bought two more syringes; they were purchased at the same time that I purchased the MX-4.  This gave me a partial tube of “original batch” and two tubes of “new batch.” I could differentiate them because the new batch syringes had holes on the syringe wrapper so that you can view into the syringe to see how much you have left (a great feature that every paste should have).  As I began testing, I started on the original batch–I had enough left for five mounts, enough to get me through the Poor Contact tests.  I was not expecting any variation in performance.

When I switched to moderate contact, it was very apparent that this was not the same paste.  They looked the same but didn’t perform similarly at all.  New batch MX-3 also had a different contact pattern.  I only had enough original batch MX-3 for five mounts, all of which were done on Poor Contact, so I can’t do a full comparison but it really does complicate the view of MX-3.

After today, we’ll have eleven TIMs completed in the 2011 Comparison, but we still have over 25 more on the docket.  Lots of testing left to do!

The TIMs

Arctic Cooling MX-3 is the big follow-up to MX-2.  After years of MX-2′s performance being matched and eventually passed by competitors, Arctic Cooling answered with MX-3.  It’s a thick, grey paste which was set to replace MX-2, only to have been killed off by MX-4.  Arctic Cooling lists MX-3 as EOL but MX-2 is soldiering on after a brief fade from market.

Arctic Cooling MX-4 is the replacement to MX-3 that also revived MX-2.  It’s supposed to be even better performing, easier to use, and lower cost than MX-3.  I feel the consistency is pretty similar to MX-3, and it behaves as such, requiring abnormally large amounts applied in order to perform to its fullest.  It’s available in 4g and 20g syringes, although I haven’t seen a 20g syringe anywhere except at Arctic Cooling’s own website.  At $6 a syringe (from AquaTuning), it has a decent but not great price per gram and a decent entry price (lowest price of any syringe size).

The Blocks

For all three contact “settings” I use a Koolance CPU-360.  I’ve chosen the CPU-360 due to its great mounting system (although I’ve modified all three blocks’ mounting systems) and because it’s pretty easy to add slight modifications.

At the “Poor” end of the spectrum, I have a stock CPU-360r1.2 with extremely low mounting pressure; the stock CPU360r1.2 has a somewhat irregular base and when paired with low pressure, TIM does not spread into a thin layer particularly well.

For the “Moderate” contact setting, I’ve taken a CPU-360r1.1 and reduced some of the internal structure so that there’s absolutely no bow.  With pressure in the center of the base the block can actually become slightly concave as the o-ring compresses, but with only moderate mounting pressure the base seems to stay perfectly flat.

As for “Great” contact, I might have gone a little overboard; no block on the market has contact this great.  I’ve modified a CPU-360r1.2 to have a thicker midplate with a compressible layer and the result is a pretty extreme bow that flattens with mounting pressure.  And there’s a lot of mounting pressure.  The result is impressive; with low viscosity pastes, it looks like there isn’t even any TIM on the center of the CPU when taking the mount apart.  Even with viscous pastes the resulting layer is extremely thin.