Arctic Cooling MX-2, Indigo Xtreme, and Spire SilverGrease

Intro

This is the first installment of many of the Skinnee Labs TIM Comparison 2011.  From here on out, results will be released in two TIM pairs roughly every two weeks but today we have three TIMs for the initial review.

Our testing methodology has changed for 2011; we’re back down to five mounts per TIM and down to ten hours per mount.  But we’ve added a large new wrinkle: testing at three different ‘contact’ settings.  By testing at “Poor,” “Moderate,” and “Great” contact, we can see how well each TIM performs across a wide range of situations.  To do this, we’re using three Koolance CPU-360s with various modifications and different mounting pressures.

Like our previous TIM reviews, we’ll also show how the TIM cures over time and how it varies across mounts.  Overall we feel the TIM Comparison 2011 will be familiar in format, just as rigorous, but with a lot more depth.

Our first three TIMs for the comparison are Arctic Cooling MX-2, Indigo Xtreme, and Spire SilverGrease.  After these three, there’s more than thirty more on the docket, so time to get to the comparison.

The TIMs

Indigo Xtreme is a totally different TIM compared to what computer enthusiasts are accustomed to. It’s not a ceramic paste, it’s not a metallic paste, it’s not a metallic paint, it’s not a liquid metal, it’s not a metal pad, it’s….something very different. The makers of Indigo Xtreme say it best: “Indigo Xtreme™ is a self-contained and sealed structure, deploying a Phase Change Metallic Alloy (PCMA) which reflows and fills surface asperities on the CPU lid and heat sink. The resultant interfacial layer is void-free and robust, with low thermal contact and bulk resistance.” In Layman’s terms, it’s a plastic card-like outer frame with a partial ring of metal that, once heated and allowed to reflow between the IHS and the cooler, forms a thin layer of metal perfectly adapted to the two surfaces. It’s a high-tech TIM.

I loved it in my initial reviews of it and that hasn’t changed. It will be really interesting to see how it performs as contact varies.

Arctic Cooling MX-2 is, arguably, the most popular TIM in the enthusiast community.  MX-2 was chosen for comparison in the initial batch as it’s been the recent standard that other TIMs have been measured against; it has Goldilocks viscosity, really good performance, and has been available in 30g syringes for reasonable prices.  On top of its good CPU cooling characteristics, it’s known for its non-conductive and non-capacitive qualities, and for being non-curing.  MX-2 has been EOL’d so

Spire SilverGrease is a newcomer to my published testing, but it’s not a TIM I’m new to.  When it started showing up in retailers, I picked up a tube in hopes it would be viable for block and heatsink testing and was pleasantly satisfied in pre-testing.  It’s an even better value than MX-2 and is just as easy to work with, but how it performs is the more interesting aspect.

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.