Some notes on applying thermal paste to the Xigmatek

I find myself linking another post with this in it, so rather than doing that I've made this post so it can go at the top of the thread. If you just stumbled across this and disagree or think something needs changing, feel free to chime in.

I write stuff not because I know it all, but because nobody else does.

Here are the exact steps I used to put on my Xigmatek:

I used a one-sided razor blade like this:

I first held the base of the cooler up to eye level and pointed it towards a light source. I then put the edge of the razor onto the surface of the base, moving it around and looking for places where the light shone in-between the razor and base.

Obviously, there are grooves between the pipes and aluminum. These need to be filled -- not because you want the contact in those areas, because the paste will be too thick there for good heat transferal. No, you want those filled so that they interfere minimally with the thermal paste you apply in the following step.

If there are OTHER inconsistencies you find with the razor method, consider lapping or, if serious enough, getting a replacement cooler. I did not feel my cooler needed any lapping. Note: A well-lapped cooler and CPU should need much less thermal paste and this method will probably need to be modified for that.

Before applying any paste, attach your hardware to the cooler (mounting brackets). I used the bracket kit, which I recommend. Push-pins suck.

Filling in the grooves:
I placed a pea sized (small pea, but ya, really) amount of AS5 onto the base of the Xigmatek. The idea is not to leave that much on the cooler, it's just to have enough to work into the grooves well. I then used the razor to work the paste around, completely filling in the grooves. This takes a little work to get just right. You want the grooves filled in, but no excess on the base anywhere once you are done. You are basically scraping the flat surfaces clean here, but leaving the grooves filled. There will be some natural "mounding" of the paste that is in the grooves... it will stick up above the level of the base just slightly. Try to minimize that, but you will always have some.

The razor works great on this step to create a flat application and scrape off the excess.

This next step is where I differ with some other folks.

Use your AS5 syringe like a pen and draw three lines down the center of each pipe, not the aluminum. Each line should be about 1/2 the total length of the contact surface. These are thin lines. (They would be even thinner lines if the CPU and cooler are lapped... perhaps MX-2 or some other ceramic paste would help here to apply a smaller amount.)

Now it's time to mount. Please note that if you got a hair stuck in the paste of some other foreign object between the two surfaces, you are probably hosed and will need to start over.

Obviously, the cooler should be placed gently and precisely so the the bolts line up with the holes. Once in place however, you should gently ROTATE the cooler back and forth. Note that the design of the CPU holder and the cooler will only let you rotate the one or two degrees. That is fine. Do this at least 5 times, then bolt it down.

Do not tighten the bolts clockwise or counter-clockwise. Use a 1-3-2-4 type crisscross pattern and make three or more passes. Never tighten one screw down all the way without first having the others beginning to tighten.

I hope this is of some use. None of these ideas are original to me, just gathered from around the internet and especially here on these forums.


This needs to be a new sticky!!

This cooler is one of the most popular coolers and the most popular design type now out. I wish I had this info. when I installed mine. I did it the "STD" way. I still get good temps (I believe) but the next I remove it, I'll reference this thread.

Good job on the info.!
Thanks. I had made a post last year when the Xigmatek was new, because I had used one and took pictures of how it fit on my board. Later I was asked about how I applied the paste and ended up writing this, but it was far down the long thread.

I just find myself linking back to it a lot so I thought it would be nice to have it in it's own post.

I have added this link and a few others at the bottom of my guide over in the homebuilt section. It's a little "how to assemble a computer" list of links. Too bad we don't have a guide here, but then we would have to do it up right if we did it at all.


May 20, 2009
umm.. Im building a PC soon and Im getting an AMD 955 and a Xigmatek Dark Iv noticed some people but a litte drop of thermal paste in the middle of CPU and spread it from edge to edge as thin as possible and than mount the heatsink.. is that a good method as well? it will nice if you could include some pics.

and is the thermal paste that comes with the cooler bad and should I get AS5 instead?

and one last thing are you suppose to get rid of your old grease and apply new thermal paste like every coulpe moths to ensue good heat transfare?
^That old method of spreading a thin layer over CPU was good for non DHT coolers. It's not good for DHT coolers any more.

You may notice a 2-5C difference between the stock thermal paste ans AS5 esp. if they were both lapped. The HSF is pretty flat, but the CPU is not. Note: Lapping WILL void your Warranty!
My problem with the "standard" method of applying thermal paste that way with a bare heatpipe-type cooler is that as the paste spreads out it will encounter those little valleys and air will get trapped in them. Trapped air = higher temps.

If the paste happened to spread out in a perfect circle with a perfectly regular expanding edge, then that might not happen. However, that's going to be pretty much impossible to achieve.


May 20, 2009
oki ill follow your method proximon but could you post a pic of the thermal paste alredy applied onto the base of heatsink if you can
If you lapp the heatsink base and the CPU heat spreader, applying thermal compound needs to be completely rethought, because the amount of thermal compound you need is almost zero.

The pea sized spread out method or the razor blade thin coat spread is applying way too much thermal compound, most thermal compounds are suggested not to use your finger because of the oils on your body.

However the finger method I've rediscovered is the best thermal compound applier of all the methods I've used in the past, use an alcohol pad to remove oils from your skin and apply a micro thin coating to both surfaces, allow no buildup what so ever, and mount your heatsink, then remove it and look at the thermal footprint.

You may be as shocked as I was to discover that the micro thin layer is almost too much, so you can adjust your thermal application to suit your actual metal to metal contact needs.

Keep in mind this is when both contact surfaces have been lapped leaving only microscopic imperfections to be filled, and I do mean microscopic.

Applying with your finger also allows you to feel the smoothness of the surfaces you're applying the compound to, just remember to clean the oils and sweat from your finger first.

Remember: The least amount of thermal compound you can apply to fill the imperfections is all you're after, for the best temperature end results.

You missed the point.
-This is for HDT coolers. The grooves in between the pipes and aluminum cannot be lapped out.
-The pea sized amount is NOT the final application.

Didn't I say?

If you lapp the heatsink base and the CPU heat spreader, applying thermal compound needs to be completely rethought, because the amount of thermal compound you need is almost zero.

I didn't miss the point I made the point, only the barest necessity of thermal compound to fill the imperfections is needed.


Are there grooves left after lapping a HDT heatsink?

Of course there is, but nothing compared to before the lapping process, but you only need enough thermal compound to fill them, so what point did I miss?

That is a Xigmatek HDT heatsink you're looking at.

If the surfaces are unlapped your method is highly viable, I wasn't trying to discount what you've written, just add to it including the possibility that someone has lapped both the heatsink and the CPU heat spreader too.


When the two surfaces are lapped and perfectly flat the amount of thermal compound needed to fill the leftover microscopic voids is actually cut by about 90%.

This is a lapped AMD skt939 FX57.
Item worth noting is that Prolimatech for example actually recommends against lapping as it decreases the performance of their milled base. It's designed to be slightly arched and made flat through the lapping process, performance actually drops.

"The base is not exactly polished in its finish, or even level against a razor blade. Taking a quick look at Prolimatech’s site, I soon found out why. The say they have specifically milled the base in this fashion as it is part of the overall designs efficiency. They do not recommend to lap this base, as it voids your warranty for one, but also lowers the efficiency of the Megahalems."

Thats exactly right, and the warranty is gone for lapping the CPU anyway, so the Heatsink warranty shouldn't really matter, its a lot cheaper than the CPU.


Jan 13, 2006

I wrap a Ziploc bag around my finger to smooth a tiny amount of AS5 across the heat pipes on my Xiggy. It seems to work well and temps are low, especially with an aftermarket fan.

The Ziploc bag or equivalent is much better than directly on your finger like I did, AS5 is extremely stubborn to remove from your skin, even with numerous alcohol pads, traces are still left behind on the skin but Lava soap finishes the cleaning, however it would be best overall to avoid the direct skin contact.


Jul 14, 2006

Hehe! The lava soap only works because it removes the first layer of skin as well as the AS5.

Next time, try using a product like Goo-B-Gone instead of alcohol. Even masking tape does a pretty good job if you run the affected skin areas across the sticky side.

Direct skin contact should be avoided, but not because the AS5 is caustic, but because the oils from your skin don't mix very well with the AS5. While I wouldn't recommend eating the stuff, it's mostly silver compounds and mineral oil, both of which aren't known to cause problems to your body at the given dosage you would encounter while applying the TIM.