Review: Thermalright AXP-100 CPU Cooler

CPU coolers are rather like cars. There’s too many variations and designs and colours and rim options, along with all the trimmings, the fake leather, park assist and the optional time-traveling knob on a Delorean that all make the choice of a cooler very difficult. Finding the one that suits your needs well enough is a bit of trial and error and at some point you either luck out on a good one, or have someone point you in the right direction for a good one. The rest of the time, it’s a gamble based on reviews you’ve read online, anecdotes from forum members and ratings on Newegg.

Thermalright AXP-100 header

In this review, I hope to save you some of that time spent looking for a low-profile, good-looking, near-silent and user-friendly cooler that will fit into a ITX chassis and not restrict your RAM choices that much – because that’s exactly what the AXP-100 is.

Lets start off with the basics of what this thing is supposed to do:

1) Keep your processor cool (d0h!)

2) Maintain a super-low profile to fit into small chassis

3) Look like a kickass piece of exhaust engineering on a monster machine

Now my PC is far from anything monster-like. Its only triple-core Athlon X3 mounted on a motherboard I bought for R800 bucks. Its not going to set any pants on fire (and thank goodness for that), but I have been loathing the stock fan for years. Although I’m deaf and can’t hear the noise of fans, what drove me up the wall more than anything was the temperatures.

Stock fans are designed to only keep things in check and make sure that AMD fans don’t need to flood your nearest PEP store looking for pants, they’re not going to be any good. So I stuck with my piece of crap for far longer than what was healthy for a gamer and, indeed, someone who writes about technology every day.

Stock AMD fan

Now to be fair, stock coolers are great money-savers. You don’t have to worry about getting a separate one because the one that comes in the box will work well enough and you can even spend, say, a year saving up for something much better-looking. If you just close up your side panel and forget about looks, then I suppose its good enough for most people.

But just look at how tiny it is – there’s not a lot of airflow going around, its only cooling one side of my memory chip, my VRM and capacitor bank don’t get a lot of fresh air and to top it off, I was actually wary about overclocking of any kind.

Thermalright AXP-100 top

During the same week I was deliberating about a new cooler, the AXP-100 fell into my lap. Its a low-profile heatsink that looks pretty much like someone took a standard tower cooler, chopped it in half and flattened the fins and then bent it in on itself. It is chromed all around and the finish is very nice to the touch. Its super-cold as well, with the six copper pipes equally distributing heat to the rack of aluminium fins.

Unlike tower coolers this is a downwards blower design, made to fit into the same sort of space as the stock cooler but with the benefit of providing more airflow for the VRM bank, the memory modules and any other circuitry around the CPU socket.

Thermalright AXP-100 bottom

The chrome finish is seen on the bottom as well and here we see the all-alumium base, but no direct heat pipe contact.. Yes, it’s coated in the same chrome paint which Thermalright says is actually good for heat conduction. The base is pretty flat, but brushed with very fine lines to allow for the heatpaste to slip in between the gaps and aid in heat transfer.

Those of you looking to get the most out of a cooler like this will likely lap the base with sandpaper to get rid of the conductive paint and the slightly rough finish. The fact that its mostly flat already helps that somewhat.

Thermalright AXP-100 extras

Thermalright provides all the extras necessary for an installation. There’s a tube of thermal paste, an application spudger, a universal bracket along with a protective metal shell for AMD socket 939 processors (that shiny squarish thing) along with the fan mounting (bottom left).

Thermalright also sent me a second fan to use with the cooler and this is a larger 140mm unit which requires the separately sold 140mm fan bracket as well. Along with that are various screws, spacers, washers and the like.

Thermalright AXP-100 header

Installation was dead easy. I removed my standard AMD retention bracket for the one Thermaltake provided, installed my cleaned processor and applied thermal new paste, mounted the cooler on using the screws provided and a Philips screwdriver and then finally fitted on the 120mm stock fan. It looks clean and neat and I rather like the minimalistic appeal this fan will have to HTPC and ITX enthusiasts.

This is your typical brushless fan that uses magnets to spin and it does that very smoothly. Nine blades slice through the air with painstaking silence and even my family had trouble picking up the sound. Being deaf, I couldn’t hear so much as a whine.

Thermalright AXP-100 clearance

There are thankfully no clearance issues with the cooler. Its right on the line with the first RAM slot on my board and makes removing modules easier. There’s open space on the other side of the socket, allowing for some really tight fitting onto ITX boards that may make even a stock cooler a tight fit. Routing the four-pin cable was a cinch thanks to the hiding space offered by the threaded bolts.

You’ll notice that I overtightened the screws slightly – this was to see how much flex was in the plastic before it would bend or give way. Even with the warping seen on the bolt to the right, the fan’s operation was fine and the plastic bent back into place easily. Solid construction with just enough leeway to show you where you’re going wrong – I like that.

Thermalright 140mm fan Thermalright 120mm fan

Comparing fan sizes was interesting. The 140mm unit is massive and so weighty. Using double-ball bearings, it spins between 900 and 1300rpm and is PWM-controlled, just like its smaller brother. Not only are the blades made out of a different material, but the plastic housing is considerably tougher as well. This fan pushes through a lot of air – up to 74 cubic feet per minute (CFM), which is quite good for its purpose.

It does sound quite annoying at its highest speed, but then I can easily counter that by setting proper speed profiles in the BIOS and AMD Overdrive. It only revs up to full speed when temperatures get really out of hand.

Thermalright AXP-100 140mm front Thermalright AXP-100 140mm side Thermalright AXP-100 140mm top

The only problem I have with it is that it’s almost far too big. As you can see, the 140mm fan does create an issue with RAM clearance and once on makes removing DIMMS in the first and second slots a very fiddly affair best left for tiny computer faeries. Even then, the DIMM in the third slot has a clearance issue and I very much doubt anyone would be able to fit in a set of Corsair Dominators. However, there is enough space for a lot of memory modules with aftermarket heatsinks, so as long as you fit this behemoth last, you’re in the clear.

The mounting plate for the fan also does allow for some adjustment. As I’ve shown here, you can move it to the default position to have some airflow on to your RAM. You can also move it to the left to blow more onto the VRM bank, which also opens up space for memory kits with taller heatsinks. The issue here is that the dead spot in the middle of the fan moves more off-center on the heatsink itself, making three of the outer heat pipes hotter than they should be. The uneven temperature reduces the AXP-100’s efficiency and may also trap heat.

Testing, testing, 1…2…3….

The test phase went smoothly and without hiccups. I ran AMD Overdrive in all four scenarios and took the average of five runs for the final score. All scores were achieved at the stock clock speed unless otherwise indicated with the Balanced profile for Windows 8 64-bit enabled. Because I don’t yet have a virgin testing environment or benchmarking hardware to use just yet, a messy, well-used install should be a good place to start.

Gaming was recorded with a few hours of Borderlands 2 along with several of my friends.In the future, this will be replaced with Crysis 3 once I have a more stable testing environment ready. Prime 95 was run at default settings and the system was stressed with Prime95 again once I had overclocked my processor to 3.5GHz

Thermalright AXP-100 temperature graph

The difference from the stock cooler to the AXP-100 is tremendous. At idle I noted temperature differences of 9° C with the 120mm cooler and a slight drop with the 140mm cooler. That same tiny gap is seen during gaming where the two fans don’t see much of a difference and the reason for that is because my temperatures didn’t go high enough to kick the bigger fan into overdrive. Prime95 showed some big gains, dropping in 10º steps for each setup. Prime kicked the big fan into full speed finally and the actual temperature kept on wobbling between 41, 40 and 39º as the fan would speed up to drop the temperature and then slow down once it had finished panicking.

Overclocked to 3.5GHz at stock voltages, the stock AMD fan soared to 70º but remained stable. The AXP-100 appears to be remarkably efficient, keeping the overclocked differences to just 5º. If I had to push on any further to 3.8GHz which my Athlon X3 is capable of, the extra voltage would probably send those figures for the 120mm and 140mm fans up to 65º and 55º respectively.

Dat Verdict…

I didn’t expect to be impressed by this little cooler and in truth I wondered if it would live up to the Thermalright name at all, given that so much focus has been on tower coolers that people might have forgotten how to build a decent blower design. The AXP is reminiscent of the popular Cooler Master Gemini which had much the same design and dimensions as well. The Gemini was much taller and wouldn’t fit into the same chassis that this would. The AXP-100 fits very nearly under the same level as the stock AMD cooler.

Thermalright AXP-100 header

But the problem here is that the 140mm unit would be a bit redundant. Sure its so much more impressive and at full speed can cool down things very well, almost as nicely as some water coolers, but it just doesn’t have the same appeal. The 120mm fan is more than sufficient and could even be fitted into chassis like the Cooler Master Elite 120 or smaller.

A detractor I found in the fan’s design was that the overhanging edge of the heat pipes impedes my ability to plug in my fans to the two 3-pin headers directly below the cooler. Its a minor inconvenience but this means that you’ll have to pay extra attention to board layout if you’re keen on buying one of these with a new parts. The fit and finish was otherwise superb and the mounting and installation was simple and effective, so I can’t fault it on those grounds.

I guess if I had to improve it, I would look at redesigning the top mounting bracket to stop the threaded screws from drilling themselves into the copper heatpipes. I would also smooth out the surface of the aluminium heasink at the bottom because the fine brushed lines make it a headache to clean properly. The cooling paste itself was of a slightly less-than-stellar quality, but given the fact that its bundled it makes little difference. Lapping the base of the cooler and putting on better thermal paste may drop temperatures about 5º C at most.

Thermalright AXP-140
Thermalright AXP-140

Locally you can’t really buy the AXP-100 because it’s already been replaced by the AXP-140, a complete redesign of the concept seen here. It has more heatpipes, more fins, more height and doesn’t ship with a fan included, giving you the freedom to pick your own one. But if you do happen to find a supplier who stocks it the flexibility on offer here is rather tempting. Its almost in the same price range as a tower cooler or even a water-cooling unit, but the AXP-100’s low height as well as the option to run it completely silent with the right processor make it a good choice for HTPC and ITX enthusiasts.

Discuss this in the forums: Linky