Corsair H105 AIO review

At first glance, the H105 is a beast of an AIO. The thing sports a 240mm radiator and comes with two SP120L fans. Being new to liquid cooling, I decided to give this a try. The reviews were great and I certainly needed something simple like an AIO to get me eased in to liquid cooling my PC. Here are some specs from Corsair’s website:

  • 240mm top-mounted radiator. Aluminum material.
  • (2) SP120L static-pressure, PWM-controlled fans. Capable of 800-2700RPM speed with 73 CFM of airflow.
  • LED-lit Corsair pump with three interchangable color rings. Power draw is 0.34 Amps. Copper cold plate.
  • Supports AM2, AM3, FM1, FM2, LGA 1150, LGA 1155, LGA 1156, LGA 1366, and LGA 2011 sockets.
  • Five year warranty.

Installation was a bit of a pain, but only because my computer was already built. I think it would have been much easier putting this into a new build versus an existing one. The instruction manual was not very helpful but thanks to YouTube I figured it out. In short, you need to install the universal back plate to the motherboard, mount your fans to the rad (I’ll discuss this later), mount the rad to the case, install the pump to the CPU, fasten, and plug in your connections. Speaking of connections, the two PWM-controlled fans are plugged into the CPU fan headers on my mobo. The pump is connected to a case fan header (more on this later).

On first boot after the installation, I was greated to a vibrant white LED on the pump and minimal noise from the fans and pump. I went into ASUS Ai Suite and set it so that the pump was running full RPMs and set the temperature levels for when my fans need to spin faster. I then started running some tests… this is where it gets interesting.

To get tests, I used RealTemp 3.70 and Prime95. I should mention that I am running an Intel Core i7-4770k which is NOT overclocked. Prior to the installation of the H105, I ran the same tests on my previous cooler, a CM Hyper 212+ Evo (this is an air cooling solution). The results, as you will see, are not what I expected.

Idle (fans at 40%): Hyper212 max was 32C, H105 max was 31C.
Prime95 Blend (fans at 100%, CPU 100% load): Hyper212 max was 100C, H105 was 90C.
Prime95 Large FFT (fans at 100%, CPU 100% load): Hyper212 max was 100C, H105 was 91C.
Prime95 Small FFT (fans at 100%, CPU 100% load): Hyper212 max was 100C, H105 was 95C.

Not what you expected from a liquid cooler, right? I certainly expected such high temps from an air-cooled solution but I didn’t expect anything close to those temps from this AIO. I checked several websites out there and it would seem that under 100% load in Prime95, most users are getting around 55-75C with their H105. This led me to think that I was doing something wrong, so I started to troubleshoot.

I first made sure that the fans were correctly connected to their headers and that my settings in Ai Suite were correct. They were. I then made sure that the thermal paste (Arctic Silver) was applied correctly so I reapplied it. I was still getting the same results. Thanks to our great YouTube community, I was given some additional steps to try:

  • Connect the pump to a 12v molex connector. I have yet to do this as I don’t have a PWM to molex adapter. Will be ordering one of those today. The thought is that my pump is not getting enough power to run at 100%, which is when the pump is at its most efficent.
  • Confirm fan placement. I have tried placing these fans in both “push” (pushing the air from inside the case through the rad) and “pull” (pulling cool air from outside the case into the rad) methods. I get the same results either way (usually a +/- 5C change). This is a highly-debated topic on the popular forums out there. May folks feel that pushing air from inside the case only works well if you have lots of cold airflow coming in. Others feel that, because heat rises, it is inefficent to pull cool air from the top of the fan since it will just heat the bottom components.

At this point, I have some additional troubleshooting options to take. I will be ordering a PWM to molex adapter to attempt and get the pump full power. I am hoping this is all it takes. If not, then I really need to troubleshoot my case’s airflow. I currently have (2) 120mm fans in the front of the case, pulling cool air in; (1) 140mm fan in the rear of the case, sucking hot air out; (2) 120mm SP fans on the radiator pushing air through the radiator and out of the top.

Overall, the design and build of this AIO is great. It is pretty easy to install and gives liquid cooling noobs (such as myself) a way to get into the world of water. Based on my observations, I feel it is no different than an air-cooler; however, the rest of the Internet is getting great results out of this AIO which leads me to believe I have a problem with my set up. I will post back here after I have tried the above troubleshooting steps.

Update on 10/19/2014:

As a follow up, I recently purchased (2) Corsair SP120 High-Performance fans for my front case. I figured with the anti-dust grilles and HDD cages that the case could be having a tough time getting air through the case. I have decided that negative pressure is the way to go so I made sure that the CFM of my out fans was higher than the CFM of my in fans (it is). I am still getting the same temps for stress tests in Prime 95. I will say that the idle temps are about 2-5C cooler since the change in fans. So I’m somewhat convinced they helped. My case is a little louder now but I don’t mind.

Next step will be finding a 12V/3-pin adapter so that I can hook up the 3 pin pump to a 12V molex. Apparently this allows the pump to run at prime efficency.

Update on 10/21/2014:

Update for you. The two new case fans I installed over the weekend are helping my idle temps slightly (I am noticing idles as low as 26C) but I still have issues when benchmarking. I have contacted Corsair customer support for their advice. More to follow!

Update on 10/22/2014:

Well, looks like Corsair will be giving my unit a RMA. I’ll have to send it in after Extra Life this weekend but once I get the new unit in I’ll report back on the findings.

Update on 2/11/2015:

A long time since an update! Corsair gave me a new unit. I installed it and I am still getting the same thermal performance. At this point I am convinced that either I have installed something wrong, my CPU lost the chip-lottery, or this cooler doesn’t perform as well as I would like. In any case, I have purchased a Noctua NH-D15 to try out. Apparently it is the best air cooler on the market. A separate video review will be posted, along with an article!


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