Earlier this year I decided to ditch my Core i7 cooler and look for something quieter. I work in the office hours each day, and keeping my working environment quiet, though a longtime desire, had become a growing concern – my CPU fan was getting older and starting to rumble a bit.
Originally, I had planned to gather several cooling solutions in the $60-$80 range to determine which was best; but in the end I decided to put just two in a head-to-head matchup:
I spent weeks with each, tweaking and measuring, and made my choice. But my choice may not be yours; the answer to which solution is best for you depends on several factors.
Up Front Considerations
Let me say before going forward that neither of these solutions is silent. They each have a level of detectable sound, even in a room with a low-to-average ambient sound level like my office, around 55dB. While silence was my dream goal, with a quad-core i7 CPU it just may not be attainable without spending far more, and perhaps not at all. Near-silent is alright by me.
I tested each cooler with an Intel Core i7 920 processor overclocked to 3.0GHz. The average temperature in my office is 73F.
Here’s a brief rundown of the components in my office PC that produce sound:
- OCZ 600MXSP 600W Power Supply [All but silent]
- NVIDIA GTS 250 Graphics Card [Silent under normal operation, i.e. no heavy gaming]
- A couple of hard drives [Clicks here and there, no fans; my boot drive is an SSD]
Though measuring exact dB levels was neither my goal nor within my hardware toolkit, I have provided some basic readings from dB Meter Pro, an iPhone app that measures sound, to give a level of objectivity to my subjective observations. Obviously more accurate sound measuring tools exist, but I was more concerned with my own observations of sound rather than numbers, which often suggest a lot without telling you anything. CPU temperature readings were obtained using SpeedFan.
Also, installing each of these cooling solutions requires removing your motherboard to install a backplate (unless your PC case has a cutout that provides access to the backside of your motherboard). If you’re not comfortable removing and replacing a motherboard, you needn’t read further. If your motherboard already has a CPU fan backplate, you’ll still need to remove it as each solution uses a proprietary plate.
The Noctua NH-D14 is a sight to behold, big and beautiful. And big. Yeah, the thing is massive, barely fitting inside my midsize ATX CoolerMaster case. Six heatpipes and two massive radiators passively move heat away from the processor, while two large fans (one 120mm, the other 140mm) move air across the heatsink for active heat transfer.
The Antec KUHLER H20 620 is an entirely different animal; a small pump and cooler plate on one end, piping in between, and a large – though still slim – radiator fan assembly on the other.
Antec KUHLER H20 620
You can currently grab the NH-D14 from Amazon.com for about $69; the KUHLER 620 is available for $58 from Amazon. I checked NewEgg and a few other favorite sellers, but Amazon has the best price for both as of this writing.
The Noctua NH-D14 (Basic Install)
My main concern with the Noctua NH-D14, upon removing it from the box, was whether it would actually fit inside my case. The unit is large, measuring about 6 inches across, 5.5 inches deep and just under 7 inches tall. But, it fit without having to do much of anything (other than surrender 80% of the empty space inside my ATX tower).
As mentioned, using the NH-D14 requires that you remove the motherboard, install a special backplate, and re-seat the motherboard inside your case. This is a pain since you have to remove all of the cables, cards, etc., but not difficult. Once the backplate and mounting assembly is in place, the fan is seated using two screws. You have to remove the inner fan to get at the screws, which is easy since each fan is held in place with clips. The kit also includes a special screwdriver for reaching the screws (most around-the-house Philips head screwdrivers aren’t long enough to pass through the opening created by removing the inner fan).
Each fan has its own three pin power cable to attach to your motherboard. The 120mm fan, the NF-P12, is remarkably quiet; the other larger fan, the 140mm NF-P14, creates an audible buzzing whir. Together, they produced enough noise to be clearly heard over the other components in my system.
From a cooling standpoint, my Intel Core i7 920 averaged 39C at normal use, and up to 53C under load (encoding video, 3D gaming).
Honestly, I figured since the heatsink was so large, and there were two big fans working to cool everything down, that the whole kit would be very quiet. But – while quieter than my previous stock cooler – the sound produced by the NH-D14 was still quite noticeable. According to dB Meter Pro, the NH-D14 used as intended raised the noise level at my office workstation from an average of 56dB to 68dB. I wanted quieter.
So, I tweaked it.
The Noctua NH-D14 (Modified Install)
I removed the inner NF-P14 fan, the larger and louder of the two, and replaced it with the NF-P12, which normally sits outside the heatsink. The one-fan result was a pleasing reduction in sound, with a slight loss in cooling efficacy. Idle or average use temps went up 3C, from 39C to 42C. Load temps rose a bit more, from 53C to 58C. Sound bumped to 59dB from 56dB. Bear in mind that these temperatures are with my Core i7 920 overclocked a bit to 3.0GHz.
If you’re not doing any major overclocking, this may be the best way to configure the NH-D14 if sound is your primary concern. You could also purchase an additional NF-P12 and use two on the system, though I’m not sure that the standalone fan includes the required clip mounts for use with the NF-P14. And depending on your system, you could even use a second silent/quiet case fan to help move the air .
Either way, by removing the NF-P14, the Noctua solution became very quiet without sacrificing too much cooling. And if you use a CPU that doesn’t get as hot as the Core i7 920 (most 2011, 2012 processors don’t), you’ll get even better temps with the single fan.
Side note: if you’re looking for an ultra quiet 120mm fan for your computer case, the Noctua NF-P12 is an outstanding choice, irrespective of your CPU cooling solution.
The Antec KUHLER H20 620 (Basic Install)
Space is certainly not a concern with the KUHLER 620 liquid cooling system; it takes up almost no space at all other than the 120mm case fan and radiator, which together are about two inches thick.
Like the Noctua, the KUHLER requires a special backplate for mounting, so you’ll have to remove the motherboard. But installing the KUHLER onto your CPU isn’t as straightforward as the NH-D14 – it requires spacers, plates, twists and turns, tricky screws and a little finesse to get everything in place. But once it is, it’s very tight and stable.
The two tubes leading from the cooler plate to the radiator can pivot about 140 degrees so you can position them as needed. It’s best if you install the system so that the Antec logo is right-side up.
The KUHLER, being a closed liquid system, can require a little extra TLC. I recommend powering it up for the first time with the cooler plate and CPU parallel with the ground; this will help work out any bubbles in the system, which can cause an audible rattle. After running for a while – if you have a tower case – you can turn the computer back upright.
The pump itself is remarkably quiet; the 120mm fan that cools the radiator, on the other hand, is not. Though Antec promises “quiet computing” with the KUHLER 620, with the included fan it’s actually quite noisy – though, again, not as noisy as the stock Intel fan/heatsink. dB Meter Pro gave an average reading of 70dB. And the fan is only a three-pin model, meaning you can’t use your motherboard to alter the speed, even if the MoBo supports this.
As boxed, the KUHLER 620 kept my system cool, averaging 37C with normal use and 56C under load. But the sound was annoying.
So, again, I did a little modification.
The Antec KUHLER H20 620 (Modified Install 1)
I replaced the included 120mm x 120mm x 25mm fan with a Noctua NF-P12. The sound was reduced noticeably from an average of 70dB to 61dB. Cooling effectiveness did suffer, however, going up to 44C at idle and 61C under load. Not terrible, but I wanted to try a second setup variant.
The Antec KUHLER H20 620 (Modified Install 2)
I tested the KUHLER 620 again, this time with a variable speed Cooler Master BladeMaster 120mm fan (model R4-BMBS-20PK-R0). This fan has a four-pin power connector that, with compatible motherboards, can have its RPM adjusted up or down based on the heat of the CPU. I connected this fan to the KUHLER radiator and my motherboard’s CPU four-pin power connector, turned on automatic fan control in the BIOS and began my tests.
This setup produced the best overall results. Under normal use, the PC sound only went up a hair from room norm – 58dB from 55dB with the fan running around 1300RPM. Cooling was equally impressive, with an average temperature of 38C performing normal computing tasks.
Under load (re-encoding a video using Handbrake), fan speed increased, along with the sound. Encoding a 20 minute video raised the fan RPM to 1630, the average temperature of the Core i7 to 56C, and the sound level to 62dB. When the encoding finished, the fan speed returned almost immediately to 1300RPM, the temperature to 39C after a couple of minutes, and the sound level to 58dB. Impressive
So… What’s the Best Choice?
I wish I were able to shout A! or B!, but as is so often the case, the results are more complicated.
If you’re an overclocker needing maximum cooling with minimal noise – or if you have a small case - I would go with the KUHLER 620 with the replacement Cooler Master fan. If you’re running a relatively cool and modern CPU at intended clock speed and have the space, the Noctua NH-D14 with the one fan solution may be better. If your CPU is efficient enough, you might even be able to get away with the Noctua heatsink alone in a case with good, cool airflow.
For my part, I chose the KUHLER 620 with the Cooler Master fan. It’s very quiet, and keeps my slightly overclocked CPU cool without taking up too much space. For most users, I’d say this is the best solution for cooling and sound. And the variable speed fan is key; it’s quiet most of the time, but can adjust when extra cooling is required.
Whichever solution you choose, you can tinker with the setup as I’ve described – or in your own way – to achieve the results that work best for you. Just be sure the resulting temperatures are within healthy levels for your particular CPU. If you fry your processor, it’s on you, Dear Reader.
Download SpeedFan to check the temperatures of your build to be sure that everything’s 5×5. It’s free.
Also, I’d love to hear your take on these two cooling solutions, or even other solutions you’ve found works best for keeping everything cool and quiet. Please email me or post in the comments section below.
M. Nichols, Products Editor