What is quietest 120mm PWM fan, HORIZONTAL mount? (for CPU)

[Scott J]

I asked about this in another Thread, but it was part of a "whole system" approach, and the original post was probably too long. My CPU fan needs to be mounted horizontally, and the archives here indicate that sleeve bearing fans don't do so well when mounted horizontally, but the SPCR recommended PWM fans are all sleeve bearing fans.

When searching FrozenCPU under "120mm PWM fans", the only one on their list that seems to be in the ballpark as far as positive reviews around here is the Scythe Kama 120mm PWM Fan (DFS122512L-PWM). BUT... it's a sleeve bearing design, so not good for horizontal mounting, if I have understood correctly.

What is anybody using for 120mm PWM fans that are mounted horizontally? Or is the best solution to use a non-sleeve bearing / non-PWM fan and just control it through BIOS or Speedfan?

Thank you!

[lodestar]

I have used the Akasa Apache PWM fan mounted on a cooler horizontally, and it was just a fit and forget job. This is one stockist in the USA http://www.sidewindercomputers.com/ak12ap57cfmi.html.

[Parappaman]

I'll never get tired recommending Arctic F12 fans. So cheap and reliable, and quiet up to 800 RPM.

[lodestar]

Yep, the F12 is another fluid dynamic bearing fan. The Apache is quite expensive compared with the F12, but in the UK it seems to be pretty popular for Core i7 setups. For example one user reports that an i7 920 gaming rig overclocked to 3.8Ghz with a Prolimatech Megahalems Rev B and a single Apache fan produces idle temps around 40C and max load around 65C.

[ame]

I use Arctic 120 PWM on a couple of systems.
On a Q6600 oced to ~3 ghz it runs 450-600 RPM, BIOS controled. Core temps are super cool 35-38 idle and 48-52 load. Cooler is TR Ulrima 90.

[NeilBlanchard]

Man, I wish I knew where this "rule" about all sleeve bearing fans not being able to run horizontally came from? And how is a "fluid" bearing different from a sleeve bearing, anyway?

What case and heatsink do you have that has a horizontal fan?

[maalitehdas]

Scythe NINJA is covering my processor and it's stock fan runs very nice under the sink blowing upwards with 150-600 RPM's. (max is 1200, but it's wired down). Inaudible in my house until 500 rpm's (which is have never reached, even under stress testing) and starts with low voltage, that's a value. It has been running there singe 11/2008 without any problems in horizontal mount.

[NeilBlanchard]

Okay -- if I recall correctly, the only fan that had an issue with this was the GlobalWin NCB and it was only when it was blowing down...

Every PSU with a 120mm fan sits so the fan blows upward, and many of those have sleeve bearings, so I think you should just use a quiet fan.

[Vibrator]

Take a look at some noiseblockers.

[Vibrator]

Okay -- if I recall correctly, the only fan that had an issue with this was the GlobalWin NCB and it was only when it was blowing down...

Every PSU with a 120mm fan sits so the fan blows upward, and many of those have sleeve bearings, so I think you should just use a quiet fan.

Sleeve bearing fans are not used in higher quality quiet PSU's. (Seasonic's, Corsair's...etc)

EDIT: Oops DP

[Scott J]

Man, I wish I knew where this "rule" about all sleeve bearing fans not being able to run horizontally came from? And how is a "fluid" bearing different from a sleeve bearing, anyway?

Hi Neil,

I don't know, that's part of what I'm trying to learn!

Sounds like maybe I didn't understand what I was reading. I was getting the impression from reading various threads that sleeve bearing fans either wouldn't last as long or would be louder (or both) if they were mounted horizontally, and getting the idea that the fluid-bearing design was not affected by orientation.

What case and heatsink do you have that has a horizontal fan?

I'm using the Silverstone FT02, which turns the motherboard 90° to the right so the I/O panel points toward the ceiling, and the MB mounts on the left-hand side of the case (window is on the right, which is apparently somewhat unusual). What would normally be the bottom of the motherboard is oriented toward the front of the case, and the video cards hang down vertically from the top of the case.

Because of this orientation, the MegaShadow's fans need to blow upward toward the top of the case (i.e., mounted horizontally), where normally they would be mounted vertically to blow toward the back of the case. With the FT02 case, the top exhaust fan and the CPU fans mount horizontally to maintain the bottom-to-top air flow design, with three 180mm fans mounted in the floor of the case.

[Scott J]

Okay -- if I recall correctly, the only fan that had an issue with this was the GlobalWin NCB and it was only when it was blowing down...

Every PSU with a 120mm fan sits so the fan blows upward, and many of those have sleeve bearings, so I think you should just use a quiet fan.

That makes the field wide open, with everything on the table. This is my first PC build, and as luck would have it, everything inside the box is oriented differently than most other PCs on the planet. This motherboard orientation seems to offer a lot of worthwhile advantages, but it can also create some unusual problems to solve.

As another example of the differences with the FT02, the PSU I'm using is a Seasonic, but it's mounted vertically at the top of the case, in the back, with the fan facing outward through a rear case vent.

[Scott J]

Thanks for all the replies.

I'll never get tired recommending Arctic F12 fans. So cheap and reliable, and quiet up to 800 RPM.

The Arctic F12 was on my list because it's a fluid-bearing design, it can be daisy-chained to other Arctic fans, and it's a PWM fan, but it wasn't listed in the SPCR fan recommendation list so I didn't know anything more about it than what their advertising says.

Yep, the F12 is another fluid dynamic bearing fan. The Apache is quite expensive compared with the F12, but in the UK it seems to be pretty popular for Core i7 setups. For example one user reports that an i7 920 gaming rig overclocked to 3.8Ghz with a Prolimatech Megahalems Rev B and a single Apache fan produces idle temps around 40C and max load around 65C.

I'm using an i7-920 with the MegaShadow, so I'll take a look at the Apache, thanks!

I use Arctic 120 PWM on a couple of systems.
On a Q6600 oced to ~3 ghz it runs 450-600 RPM, BIOS controled. Core temps are super cool 35-38 idle and 48-52 load. Cooler is TR Ulrima 90.

Another good report for the Arctics...

Scythe NINJA is covering my processor and it's stock fan runs very nice under the sink blowing upwards with 150-600 RPM's. (max is 1200, but it's wired down). Inaudible in my house until 500 rpm's (which is have never reached, even under stress testing) and starts with low voltage, that's a value. It has been running there singe 11/2008 without any problems in horizontal mount.

Scythe Gentle Typhoons, S-Flex and "Kama Flow" all seem well liked, I'll check to see if the fan that comes with the Ninja is one of those.

Take a look at some noiseblockers.

I'll check out the Noiseblockers too, thanks!

[Scott J]

Man, I wish I knew where this "rule" about all sleeve bearing fans not being able to run horizontally came from?

Hi Neil,

I think this is where my questions/concerns about sleeve-bearing fans started, from SPCR's Fan Round-Up #2: 120mm Fans:

"Aside from that, the only disadvantages are shared with Nexus' 80mm fan: Closed flange screw holes that make wire clips unusable without modification, and sleeve bearings that are inappropriate for horizontal mounting or high heat situations. Together, these ensure that, while the Nexus is an excellent choice for a simple case fan, it is less suitable for mission-critical operations such as a CPU heatsink or a hot power supply." (emphasis added)

http://www.silentpcreview.com/article69 ... html#nexus

He was only talking about the Nexus 120mm and 80mm fans specifically, but I (mistakenly?) generalized the comments about the sleeve-bearing design to ALL fans. I have read other posts making similar comments, quite possibly inspired by this same SPCR Fan Round-Up article.


On a different note, I read this in the same article linked above:

"A word of caution: Much of the low frequency noise is present as vibration as well as sound and can cause resonance if it is hard-mounted. At lower fan speeds, the vibration is so low that this is not a concern, but those using the fan at high speed may find that soft-mounting with silicone grommets may help cut down the low frequency rumble that this fan produces."

I think this is describing a very strange noise that I noticed for the first time last night. It comes and goes, and was not easy to isolate. The best way I can describe it is like the sound from the laboratories in old Sci-Fi or horror movies (e.g., Frankenstein). It's a low, rhythmic, pulsating electrical hum. I thought maybe my power supply was going bad, but when I put my ear up to it, it did not seem to be the source. It didn't seem to be emanating from any one place, but with the TV muted and everything else quiet, I could here it from more than 10 feet away.

It was loud enough that I thought maybe it was the house furnace, because the heating ducts are nearby, so I turned the computer off and the sound stopped immediately. Turned the PC back on, and there it was again. When I read the quote above about resonance, I tested my three 180mm bottom case fans, and I'm pretty sure that's the source of the intermittent electrical hum or resonance.

How do I fix that? Does anyone make 180mm rubber fan gaskets?

[danimal]

you can sometimes unplug the fans while the pc is running, and tell which fan is making the noise.

worst case, power the fans with the computer off, using a seperate power supply, that way you'll be sure that you are targeting the source of the noise.

the only 120mm fan that's ever failed on me was a sleeve bearing case fan that came with the p182... and it was mounted in a horizontal position, it didn't actually quit completely, it just started making noise... i tried oiling it behind the label, nothing helped.

[Mr Evil]

Man, I wish I knew where this "rule" about all sleeve bearing fans not being able to run horizontally came from?..

Every single sleeve bearing fan that I've used horizontally has ended up unbearably noisy within a year. Maybe some work alright, but I find it easier to just keep them all vertical.

[Parappaman]

The "rule" comes from the FACT that sleeve bearing fans use oil as their only friction-reducing mean, so if the fan is mounted horizontally the oil gets either on top or at the bottom of the bearing, not INSIDE it. If faced with high heat, it will also evaporate sooner. This leads, in the long term obviously, to a sooner-than-expected degradation of the bearing sleeves, and as we know that means more noise, and, perhaps more important, a fan spinning slower and slower over the time.
FD bearings are superior, but check Google to find out what they are and how they work, it's a long story and there are many variants.

[BillyBuerger]

My story is that we had 4 cheap PSUs in some PCs at work and within two years or so, all of the sleeve bearing 120mm fans froze up on them. Although these were definitely cheap fans and all the same brand. Maybe some are better than others.

I had an AC 120mm PWM fan in my desktop PC here. But it seemed to have a bit of clicking that was noticeable at low rpms. Enough that even with the back of my PC 4ft away from me, I could notice it when the heat wasn't running in the house. I've since switched it with a Gelid 120mm PWM fan. This is also an FDB fan much like the AC. It too has some clicking but seems quieter. Enough that I'm happy with it and don't think I'll swap it for anything else. But it could have just been a bad AC or a good Gelid fan. Some of it is luck of the draw.

[NeilBlanchard]

I think that how long a bearing lasts in any particular situation is determined by the quality of the bearing design and how well it is made. Some ball bearings wear out prematurely, too!

The oil is impregnated into the sintered metal (bronze?), and if the surface area is adequate, and the shaft is sufficiently smooth and hardened, and there is enough oil in the bearing, then it will last a very long time.

If the surface area is too small, or if the shaft is out of round or not straight enough, too rough, or too soft, or there is not enough oil in the sintered metal -- then it wears out in less time than it should.

Same goes for a ball bearing -- if the balls are not consistent in size, or if the races are out of round, or too soft, or if not enough oil is used (it can only have oil on the *surfaces*; unlike a sleeve bearing!), or if the shaft isn't straight -- then it wears out prematurely.

The bearing in my Linn turntable is a sleeve bearing -- and it will outlast you an I, both. Oil has an amazing ability to bear a LOT of pressure, and if it is properly designed and made and the oil is maintained, it will last. Virtually every vehicle engine on the road today has plain bearings.

The irony of this "rule" is that the GlobalWin NCB fan that started it (I think it was a post by Felger Carbon noticing that this fan slowed down when blowing down? <--- I found the post! Look at the last two paragraphs!) -- has ceramic sleeve bearings that will last a very, very long time in a hot place like a PSU, without oil. And, it was a quiet fan, to boot.

Fans in PSU blow upward, right?

[Scott J]

The irony of this "rule" is that the GlobalWin NCB fan that started it (I think it was a post by Felger Carbon noticing that this fan slowed down when blowing down? <--- I found the post! Look at the last two paragraphs!) -- has ceramic sleeve bearings that will last a very, very long time in a hot place like a PSU, without oil. And, it was a quiet fan, to boot.

Fans in PSU blow upward, right?

Mine do! Thanks for finding the link, too.

The bearing in my Linn turntable is a sleeve bearing -- and it will outlast you an I, both.

On that note, I bought a VPI Scoutmaster when I went back to vinyl about 6 or 7 years ago. For my next TT (hopefully, someday), I'd like to audition both a vintage refurbished Linn, and a refurbished Garrard 301 (circa 1950s, for those who don't keep up with record players anymore )

And now, back to our regularly scheduled programming...

[Parappaman]

Turntables and cars cost several times more than a computer fan, it's obvious they can afford using more advanced components to build them!

Standard sleeve bearings use teflon as sleeve material, not metal, which is basically plastic, so they last shorter. There are variants that are made better (ceramic sleeve, rifle bearings and so on) and obviously the high quality ones suffer less from orientation and drying issues, but the "rule" still stands.

[NeilBlanchard]

I have taken apart a few fans, and I have never seen one with a Teflon bearing -- all have bronze bearings.

My 1/24th scale slot cars have the same "oil lite" bearings on the rear axle and in the motor. These need oiling because the motor spins at ~30,000 RPM and the shafts are not always straight, and the armature is never in perfect balance. The axle spins at about 2,000+ RPM and the hardened steel axle wears out at about the same speed as the bronze oil lite bearings.