New 2.26 (2009) Mac Pro Humming Noise

[bearcatrp]

These last two posts make me think that Apple is buying fans from a supplier that is producing unbalanced fans.

HQ Fans are like $20 a piece. You can test this by changing the fan speeds and see if the noises (pitch etc.) also change. If they do then that's it! So it's just $100 to replace all the fans in an octad 2009 with HQ ball-bearing silent running ones. I guess it'll take about an hour to do all of them. Might be fun too! Some HQ fans come with pretty multi-color LED illumination too.

Tesselator, are the fans standard to use in mac and pc? I didn't think you could use anything but apple parts to replace things like the fans. One thing about my upgrade on the 2006 mac pro is i have to keep my fans at 1400 rpms while crunching data 24/7 and figure they will need replacing sooner than normal time. So if off the shelf fans can be used, would probably be cheaper.

 

[Tesselator]

I installed a fan controlling software and increased the fan speeds. The speed and pitch increases and the sound becomes even more appearant. I'm pretty sure the fans are unbalanced. I went down to the store today and put my hands and my ear on the 2008 mac pro's. They weren't vibrating or humming at all, even pressing my ear against the chassi... I only heard the "air" sifting through the machine.

Tesselator, are the fans standard to use in mac and pc? I didn't think you could use anything but apple parts to replace things like the fans. One thing about my upgrade on the 2006 mac pro is i have to keep my fans at 1400 rpms while crunching data 24/7 and figure they will need replacing sooner than normal time. So if off the shelf fans can be used, would probably be cheaper.

All of the fans I've ever seen in all of the computers and electronics I've owned over the past 25 to 30 years conform to some specific industrial standard not having anything to do in specific with one platform or another. The form factor of muffin fans although their popularity and growth seems to have paralleled the popularity and growth of computers, seems to be specification-independent from any given computer manufacturer. There are five basic types of bearings commonly used in computer fans that you should be aware of when selecting replacement fans in a situation like this:

1. Sleeve bearing fans use two surfaces lubricated with oil or grease as a friction contact. Sleeve bearings are less durable as the contact surfaces can become rough and/or the lubricant dry up, eventually leading to failure. Sleeve bearings may be more likely to fail at higher temperatures, and may perform poorly when mounted in any orientation other than vertical. The lifespan of a sleeve bearing fan may be around 40,000 hours at 50 °C. Fans that use sleeve bearings are generally cheaper than fans that use ball bearings, and are quieter at lower speeds early in their life, but can grow considerably noisier as they age.
   
   
2. Rifle bearing fans are similar to sleeve bearing, but are quieter and have almost as much lifespan as ball bearings. The bearing has a spiral groove in it that pumps fluid from a reservoir. This allows them to be safely mounted horizontally (unlike sleeve bearings), since the fluid being pumped lubricates the top of the shaft. The pumping also ensures sufficient lubricant on the shaft, reducing noise, and increasing lifespan.
   
   
3. Ball bearing fans use ball bearings. Though generally more expensive, ball bearing fans do not suffer the same orientation limitations as sleeve bearing fans, are more durable especially at higher temperatures, and quieter than sleeve bearing fans at higher rotation speeds. The lifespan of a ball bearing fan may be around 63,000 hours at 50 °C. They are also generally noisier than types 4 and 5 listed below but perhaps are the most commonly used in computers in the past 7 years or so.
   
   
4. Fluid bearing fans have the advantages of near-silent operation and high life expectancy (comparable but a little better than ball bearing fans). However, these fans tend to be the most expensive. The "Enter Bearing" fan (a sixth type) is a variation of the fluid bearing fan, developed by Everflow.
   
   
5. Magnetic bearing or "maglev" fans, in which the fan is repelled from the bearing by magnetism. These are perhaps the quietest and most long lived fans available.
   
   You'll probably want to select type 4, 5, or six for your needs.

And of course there's also amperage, voltage, and the type of current to consider besides the physical dimensions, when choosing appropriate replacements. Apple doesn't directly advertise the electrical specifications of the fans they use but I believe their service manuals lists them as well as some Macintosh replacement part shops on-line. Common fan sizes include 40, 60, 80, 92, 120, 140, and 200 mm. A ruler will tell you quick enough for the dimensional specification.

All this makes it sound troublesome or difficult but it's really not. It's pretty easy. Maybe the hardest part would be finding out the specs for the ones Mac uses but even this should only take about 10 to 15 minutes to locate on-line.

I attached an image of the 2006 front fan (part No. 922-7699) for reference. (http://www.welovemacs.com/9227699.html) This site: http://www.xlr8yourmac.com/tips/MacPro_HD_in_optical_drive_bay/MacPro_HD_in_OpticalBay.html also has some information on making HDDs run more quietly.

Let me know if you have any other questions.


.

 

[nanofrog]

For the location/use, fluid or mag lev bearings would be the best way to go.

 

[Tesselator]

Yep!

Also here's an interesting and LOOOOOOG article I came across while fact-checking that might be interesting to the chronically bored among us here:

http://www.xbitlabs.com/articles/coolers/print/120-140-fans-roundup.html​

.

 

[planetdom]

mac pro humming noise fix

Hi i have had my mac pro for 6 weeks when all of a sudden i started to get a humming,oscillating sound that drove me mad i thought it was the power supply,Then (This is the best bit)i came across ISTAT menus (bjango.com/apps/istatmenus/)After a lot of playing around i found a section called Sensors and then click on it,once opened there is a section that says fan speed,click on edit rules,once opened click the plus sigh,this will give you Untitled set then on the intake section i changed it from 600 rpm to 612 rpm may have play around with the settings,Then set the use as default set to Untitled set then click on the thp on the right hand at the top of the screen select fan speed control to untitled set then hopefully you shouldnt hear a more noise...The best time to play around with these settings is at night when every thing is quite...if any one reads this and dont understand then i can make a youtube video to help

 

[planetdom]

New 2.26 (2009) Mac Pro Humming Noise fix

Hi i have had my mac pro for 6 weeks when all of a sudden i started to get a humming,oscillating sound that drove me mad i thought it was the power supply,Then (This is the best bit)i came across ISTAT menus (bjango.com/apps/istatmenus/)After a lot of playing around i found a section called Sensors and then click on it,once opened there is a section that says fan speed,click on edit rules,once opened click the plus sigh,this will give you Untitled set then on the intake section i changed it from 600 rpm to 612 rpm may have play around with the settings,Then set the use as default set to Untitled set then click on the thp on the right hand at the top of the screen select fan speed control to untitled set then hopefully you shouldnt hear a more noise...The best time to play around with these settings is at night when every thing is quite...if any one reads this and dont understand then i can make a youtube video to help

 

[planetdom]

(2009) Mac Pro Humming Noise

My mac pro started to make a humming,oscillating sound that drove me mad i thought it was the power supply,but i found that unpluging the intake and rear fan the noise completely stoped,so the colprit has to be the 2 fans not the power supply that i thought it was....I also found that upping the rear fan from 600 to 612 helped the situation...

 

[Redhawk2006]

I have no idea if you can hear that noise at all - but here you go: recorded with the mic being placed on top of the Mac Pro case.

Yes, I can definitely hear that noise and it is exactly the same oooooWAAAAA ooooWAAAAA sound I was getting with my 2008 Mac Pro. After replacing the PSU and a couple of fans, Apple recently replaced my old Mac Pro with a new 2010 Mac Pro and I am getting the same noise from this unit. It is actually worse than my old unit, even with nothing but the stock harddrive in it.

The fact that some people can't hear this is interesting, as the sound is obvious to me: there is one steady drone from the fan, and the low frequency, oscillating oooWAAAA sound in the background.

In my opinion, the sound is coming from the PSU and/or the PSU fan. Whether there could be some power fluctuation in some people's homes hat maybe accounts for this I don't know. It could be that some minority of us are just sensitive to this low frequency noise while Apple's engineers can't hear it.

 

[rezwits]

I know this may be Necro-ing but, I just recently went thru this with my 2009 Mac Pro. I went and got some canned air duster and blew out the fans, but that didn't really get things cleared out as far as the noise at least. So, I downloaded smcFanControl.app. I switched the machine to a different less used power strip, zapped the pram, shutdown, reset smc, restarted, zapped the pram, then launched the smcFanControl.app. In the fan control app, I went to each fan and set each one to about 75% of max and then back to minimum, one by one. I restarted the machine, and the humming noise, which I am pretty sure was the PSU because the fan changing in the app didn't seem to alter the sound, but after doing all the tips at once, the humming noise is gone! GOOD LUCK.

 

[iBuildMacs]

The sound is most likely coming from a fan. The best way to figure out which fan is to put your ears next to the fan. To confirm, put a small screw driver into the fan while the Mac Pro is on. If the sound stops, you found the problem. Stopping the fan for only a few seconds will not cause damage.

A sound coming from the processor heatsink fan is rare, but possible; it's happened maybe once in the 1000s of units I've worked on. If it is, you will have to replace the processor heatsink. If it's a dual processor unit, I suggest against changing the heatsink yourself. You might bend the pins on the processor board.

 

[h9826790]

The noise from a multi fan system can be very complicated.

If that only come from a single fan. It's easy, usually alter the fan speed can temporarily fix the problem (until the fan wear more, and its characteristic change).

However, another possibility is that the final "beat frequency" is the "resultant noise" from more than one fan's noise. In this case, the frequency usually much lower than the original one (low pitch), and may only affect a specific area (due to the nature of interference. The worse area may be 1-2 feet away from the Mac, but not right next to the fan). It's much harder to fix this kind of noise. Because the noise characteristic will still be changed when the fan RPM change. So the user tends to believe that they found the source, but still very hard to remove the noise by changing the fan RPM (because it's just one of the noise component).

Another common misconcept is that the user manually spin up the fan, and then realise the noise gone even the fan back to idle. Sometimes it's true, but more chance is just because your ears was "adopted" to the high fan noise. So, the machine now is "relatively" quiet right after the fan back to idle. A little bit like our night vision is poor when coming from a bright area. This "max fan speed" method usually fix our ear, but not the machine. So, the user will complain that the noise come back after a certain period of time, once their hearing is back to "normal".

Also, to fix some humming noise, you may just need to tighten few screws, not necesseary fix the fan. The vibration is coming from the fan, but the noise may be coming from something else. From memory, there was a member here suffer from this kind of noise, try many fix, nil help. And the finally fix is to put a piece of paper between the processor cage and the case to stop the vibration.

 

[friolz]

My GPU, a Gigabyte R9 280X is a full-length PCI card. It's resting on top of the CPU compartment, thus transmitting vibrations to aluminum housing.

My question: Is there a frame which I could buy that allows me to attach the graphics card to the PCI mount (part of the Expansion Slots fan)?