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PE 2950 Fans Loud as JetsRecently we purchased a Dell 2950 III with a DRAC card to investigate adding IPMI support to PA Server Monitor

So far it's great, but what wasn't so great was the noise.

One blog writes that it sounded like a fleet of jets all taking off at once from an aircraft carrier.  I thought it sounded a little more like an air raid siren I've heard on movies, or a tornado siren that we hear around here.  It actually causes ear pain with the case open. 

To be fair, the volume does go down with the case on and after the system takes a few minutes to lower the fan speeds, but it's still way too loud.

 

So, This Fan Noise is for Real?

After some quick investigation, it became apparent that the bulk of the noise came from the four Dell cooling fans (for reference, fan model number was F126025BU.) 

These things are beasts. 

If they were mounted in the right direction you might think they could lift the server into the air.  Because this server will be in an office environment, a low noise level is a must.  And since it won't be heavily loaded, cooling capacity isn't as important.  With that in mind, we bought some quiet consumer-grade fans.  Two things are important when you're looking at replacement fans:

  • The original dimensions of the fan are 60mm x 60mm, so the replacement fans should be the same size.  IIRC, the originals were also 38mm deep, but virtually all replacement fans will be less than that since they don't have has large a motor, and smaller is OK in this case.
  • The replacement fan needs to be a four-pin fan with PWM control.  This is how the motherboard controls and probes the fan's speed.

 

Small List of Suggested Items and Tools You Might Need

  • Replacement Fans
  • Band Saw or Hack Saw (to cut plastic)
  • Soldering Iron
  • Couple Pieces of Solder
  • Wire Cutters/Strippers
  • Heat Shrink Tubes
  • A hot air gun if you have one (like on a rework station), or…
  • Lighter/Grill Lighter or Matches
  • Plastic Ties/ Computer Wire Ties
  • Magnifying Glass and mount (if your eyes require it)

 

DISCLAIMER: We can't be held responsible for any damage you do to your system! This set of tutorials is not intended for anyone not willing to take a risk of using fans that could possibly cause the server temperatures to get too hot (which obviously could be bad.) This is directed to those who might have these servers in their homes, or small offices where you might not have a server room. It is intended for anyone that might have powered down their servers and stored them away just because they can't take the noise anymore. If you fit this description, read on.  : )

 

Remove the Fan Bracket

Once you pull the fans out (by lifting on the orange handles), you'll need to free each original fan from its bracket.  This just takes a little inspection and pressure in the right places.  You should end up with three pieces like this:

Dell PowerEdge 2950 Server Fan

 

Making the Cut

With your wire cutters or wire strippers, carefully cut all the wires in one cut (making the cut somewhere in the middle or a bit towards the old fan.)

 

Dell PE 2950 Fan Wiring

 

The gray connector (bottom right), and the surrounding attached black plastic bracket (not shown here), will be rewired and connected to the new fan (top left). Make sure you strip about a half inch of the plastic off the ends of all of the wires shown below.

 

Dell PE 2950 Server Fan Wiring

 

The New Fans, and the Old Fan Seating Don't Match

Taking a quick step backwards, if you look at the seating where the fan is inserted, you will notice as shown below, there is a ridge of plastic that is necessary to stabilize the fans when they are placed and locked in. You can see this a bit better in the magnified area in the right side of the image (which is also enhanced a bit to point out just where the piece is.)

The new fans do not play well with this plastic ridge and have a protruding side that prevents it from sliding down into place. This is the main reason you’ll need a band saw or hack saw, which we’ll get to here in just a bit.

Please note: NO CUTS are going to be made anywhere on the inside of the server. The cuts will ONLY be made to the new fans before reinserting them into the server.

 

Dell PE 2950 Server Fan Brackets

 

In the image below, you can see the final cut on the corner of each fan casing (only to the offending corner of each fan that prevents them from sliding into the server fan slots.)
We'll discuss how and where to make the cuts next.

 

Dell PE 2950 Fan Casing Modifications

 

Making Cuts to the Fan Casing to Fit in the Server Fan Housing

Below is a view from the back side of the fan, showing both of the cuts that are needed. Notice we also need a notch cut at the corner closest to the wiring from the fan. We’ll discuss the notch cut more in the next image.

 

Dell PE 2950 Fan Casing Cuts

 

When the new black outer bracket (containg the gray connector) is placed around the fan, you’ll notice right away the wires will be creased up almost flat against the fan itself (as shown in the image below of a unit that is nearly finished, showing wire placement.) To relieve the pressure and creasing, you’ll need to also cut a notch to allow the wires room to come through.

 

Dell PE 2950 Fan Casing Modification

 

This photo shows a little bit better view of how and where you should make the notch cut with your blade saw or hack saw. You may even be able to make all cuts with a Dremel tool, but you’ll have to test that yourself.

 

Dell PE 2950 Fan Bracket Cuts Topview

 

 

Wiring Diagram: Old Fan Connector to the New Fan

IMPORTANT! Matching up the correct wires from the old connector to the new fan is crucial. Seeing as the old fans sound like a fleet of fighter jets, rewiring the fans incorrectly just might cause the universe to implode. So for the sake of civilization, please read this carefully!

Unfortunately, the colors of the wires do not sync up between the two fan parts. And even more unfortunate, the wire colors are not always consistent, even among the exact same models of fans.

To account for this, we have tested to find which wires, according to their connectors, serve what purpose. If you notice, we have grayed out the wire colors intentionally. This is because you should pay no attention to wire colors when connecting. Of course, some will be standard, like black, which will nearly always be the ground wire. But better to be safe and follow the chart below.

Just make sure you match up the wires in the left image (from the old connector) to the wires in the right image (from the new connector that will be discarded), as noted by which spot the wire comes out of the connector. So also make sure you are looking at the connector in the same position as shown below.

 

Dell PE 2950 Fan Wiring Diagram

 

You’re now ready to start soldering the wires together between the old gray connectors and the new fan units. You might want to remove the gray connector from the black plastic bracket until you have all the wires soldered together.

 

Soldering the Wires Together

First, make sure you have a heat shrink tube placed over each wire as noted below (this one happens to be clear, but the tubes in folowing images are light blue) before soldering. Push the tube all way up close to the fan so it doesn’t get in the way.

The ends of each wire should be sort of “frayed.” Leave the wires this way…you don’t want to twist the ends to make them more pointed. You will take the ends of each wire and push them together, so that the “frays” sort of intermesh with each other.

Then, carefully place the soldering iron under the wires at the point where they connect, and gently touch the bare wires for a moment. With the solder wire in the other hand, touch the solder wire to the top side of the connecting wires and quickly melt just a drop or so onto the wire. The picture below should help visualize how to do this.

This may take a little bit of practice before you get the hang of it. Or, you may want an extra set of hands to help if you’re having trouble holding all the pieces together while you try to make the solder.

 

Dell PE 2950 Fan Heat Shrink Tubes

 

Read on to see the final steps "Dell PowerEdge 2950 Server: Quieting the Loud Fans!" – Part 2 >>>

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William Thompson

William is the Marketing Manager at Power Admin, a server monitoring software business in the Kansas City area. You can find him on Google+ and Twitter. William has been a professional in website design, marketing and 3D/graphic design for over 20 years.

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24 Responses to Dell PowerEdge 2950 Server: Quieting the Loud Fans!

  1. Popescu Dan says:

    Thank you William for sharing this article with us!

  2. Felix says:

    Thanks for this nice article, regarding the sensors making the fans throttle full speed, you may be interested in this article: http://projects.nuschkys.net/2011/08/23/the-battle-againt-the-bmc-%e2%80%93-part-2/

     

  3. felix says:

    Nice article – you may be interrested by this article to get rid of the sensors making the fan throttle to full from time to time: http://projects.nuschkys.net/2011/08/23/the-battle-againt-the-bmc-%e2%80%93-part-2/

  4. evok says:

    Hi William

    Thanks for the great post.

    Just wanted to ask what type of fans do you reccomend i'm going to try this too for our office server which is the same. But not sure which fans to buy.

    Thanks

  5. Hi, this is what worked for us, for this particular server. (information taken off the back of the fans)

    Original Fans:
    Type/Make: NMB-MAT (Minebea Motor Manufacturing Corporation)
    Fan Part ID#: YW880-A00
    Model: 2415KL-04W-b96
    (DC 12V, 2.10A, 67CFM)

    New Fans:
    Make: Everflow
    Model: F126025BU
    (DC 12V 0.26 AMP)

     

    Hope that helps!

    Let us know how it works out for you if you decide to give it a go.

    -William

  6. Adrian says:

    Dude! I just did this and it worked great! My system temp is at 25*C to 26*, an uptick of maybe 1 or 2 degrees. My server is just in my home and I could hear it from the other room, thus keeping me awake at night. I used the same Everflow fan you mentioned in your commects, although at first I mixed up the RPM and PWM wires, the server freaked and spun up the fan on the power supply to full blast, which makes a ton of noise. However, once I fixed up the wiring all was well once more. 

    One thing I ran into that you may or may not have run into yourself is 2 of my fans were put to 1600RPM once the server did it's check. So again the PSU freaked. I actually ended up moving Fan 1 from Bay 1 to Bay 3 and … voila! Problem solved. Right next to the server we have just about 35 to 40db. The other room is completely silent.

    Also! I didn't chop off the entire end like you did on the fan, since I wanted it to fall back into the cage and be able to clip back on. I took a dremmel tool and just carved out the part that needed to go so that it could seat itself in there all nice. That way I still have my plug and play fans. 

    That's it… thanks again!

    A.

    • You’re very welcome! Great to hear it worked as well for you as it did for us. :)

      • Adrian says:

        Howdy, 

        Quick update… since I noticed you were having an issue with the fans ramping up to full blast every 5 minutes or so. For the first server I tweaked this was not an issue ( I bought 7 poweredge servers .. accidentally… long story ). The first server didn't have a problem because all of the fans ran at relatively the same speed. I found that in my other servers/fans this was not the case, thus the problem mentioned above reared its ugly head.

        I ended up having to flash the BMC Firmware with lowered fan thresholds. My Poweredge servers are all 2950 2nd and 3rd gen. So my original threshold was 2025. I set it down to 975, they have to be multiples of 75… Anyway, here is how I did it:

        http://projects.nuschkys.net/2011/11/15/how-to-adjust-the-fan-thresholds-of-a-dell-poweredge/

        Things to note:

        1) If you use Ubuntu for the patching  process you will have to get some stuff that is available to Red Hat distros such as rpm and change some things in the environment. This is because the Dell Firmware is written for Red Hat. Here is what I mean:

        http://wherethebitsroam.com/blogs/jeffw/running-dell-update-package-red-hat-linux-debian/

        2) If you get package stuff like this:

        E: Unable to locate package freeimpi
        E: Unable to locate package freeimpi-tools
        E: Unable to locate package impitools

        run: sudo apt-get update (thats off the top of my head, you just have to update apt-get package lists, this was an issue in Ubuntu 12.04)

        I also could not get impitool for some reason so I just skipped it. This had no effect on the process. I was still able to complete it. 

        3) You will have to unzip the "hapi" folder manually, just look for how in the comments of the tut linked above. 

        4) I'm pretty sure I'm forgetting stuff… So be careful when you do this if you are reading this comment and aren't experienced. Follow all disclaimers on both of this site, and the one linked above.

         

        That's it for now, overall the process wasn't bad, I'm not a *nix admin by any means and I was able to do this… My servers are still running at 26 to 27 C so there is no visible impact of replacing the fans to the board ambient temp. The sound though … is nice :0) we're somewhere in the 30 – 40db range. The fans are running at roughly 2000 – 3000 RPM now since the machines heated up… they keep each other warm.. HA! Maybe I didn't need to flash the BMC Firmware :0)

        Hope this helps someone …

        Cheers,

        A.

        • Hi Adrian,

          Thanks for the update. Sounds like you got that ramping fans issue under control now. Great stuff, and I bet we’re not the only ones that have encountered this!

          Let us know if anything changes.

          Cheers!

  7. Sam says:

    I cannot thank you enough for posting this!  The instructions worked incredibly well and my server has gone from something that terrified my cats, to a large box no more loud than my previous server.  The only hiccups I had were on Dell's side, namely that their flashing suite (at least the only one I could find for the 2950) refused to do anything on a non-rpm (Fedora, CentOS, etc.) system and the utility itself would only run on a 32-bit architecture.  

    It's guys like you that make Linux and its associated distros, the greatest collection of operating systems in existence. Thank you.

  8. evok says:

    Hi Guys 

    I followed the post and got my fans installed. I used the same fans reccomended. I had to order them from China had trouble sourcing them to the UK.

    Just wondering what RPM you guys are getting and what temp

     

  9. dsal says:

    I ordered my fans from CWC Group and they were out of the Everflow fans and substituted Protechnic MGT6012UB-W25  17797  60MM Fans.

    Wiring colors matched Dell's exactly so made it super simple.  Probably took an hour and half for me to get through this – and was it ever worth it!  I have been disappointed since the day I bought this server 6 months ago over the noise.  I've got it in a GizMac quiet enclosure and it's still way too loud.  Problem solved!  Awesome instructions!

    My fans are running at just under 5000rpm's and server administrator shows a minimum of around 2000, so I am hoping not to get the ramp up issue.  Ambient board temperature at 28c.

    Thanks!

  10. Mike Johnson says:

    I had some 60mm x 60mm spare fans in my house (which i obviously always keep for future use) and just installed them like the manual said. The result is wow !

    Now I can have a better sleep at night :)

  11. I really needed to get rid of this horrible noise making fans, thanks a lot for sharing this. Though getting a new one which fits in there was not quite an easy task I would say. But yet, it was helpful.

  12. Nice tutorial friend with good details you can visit here at http://greatcpucoolertuts.blogspot.com for more tutorial about modding a fan.  

  13. dg says:

    Just completed this mod on a Dell 2950.
    I modified the BMC (v.2.50.00) firmware, and have a minimum RPM of 975, which you can see in Open Manage.

    I did not replace the fans – Instead, I used 68 ohm resistors in parallel (34 ohms resistance) – which also cuts the current through each in half (no more getting warm).  You've got to stuff them in there, but they work just fine.  Cost was about $4 for 8 resistors.

    I see some cycling of fan RPM, but it is so quiet that I don't notice it.
    Per OpenManage, they are spinning at 3100-3900 rpm range.. they seem to be cycling in that range, probably due to a big decrease in current.
    I have memory in "low power" mode.
    System board is at 31 C.
    The system pulls 227 watts, down from 230-235 before modifying the fans.

    This brings my system down to 53db outside the case.  Before, I could hear it across the house.

     

  14. Evok says:

    Hi Guys

    I did the swap as the post suggested (thanks for tutorial) I used the fan suggested (F126025BU)

    But there's still a fair bit of noise coming from the server and the Fan readings for Fans 2,3,4 = 5475rpm and fan 1 = 5625.  With -/+ 1000 rpm fluctuations 

    Any Ideas?

    Thanks

  15. Hi Evok,

    You might check out Adrian's post earlier in the conversation above about a possible fix for the ramping fluctuations.

    If you try that, let us know if it works for you. Other than that, we haven't found any other fixes except possibly searching for quieter or slower fans.

    • Evok says:

      Hi William

      Thanks for getting back

      In reference to Adrians post. Theres two things he looked at the mix up of the wires or the moddification of the firmware. Which one do you suggest I should look in to ?

  16. Duncan Fitz-Gibbons says:

    Hi,

    I had a similar issue and found that upgrading the BIOS cured it. The BIOS wasn't detecting the temperature probe so the fans just ran at top speed by default. Updated the BIOS and it has cured it.

    Cheers

  17. CHINNIAH says:

    memory / battery problem were detected.the adaper has recovered ,but cached data was .press lost key to continue.orto load the configuration utility  

  18. dler says:

    make a short circuit of B2 & B3 pin from power supply might be a solution too, the fans will work under low speed always.

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