This is my first post, so I apologize if I'm not following any particular protocol or have posted this in the wrong category; please let me know if I need to change or re-post elsewhere. (thank you)

I have a Dell Precision T7400 that came equipped with a single E5405 processor (2 ghz Xeon); on this processor was just a heat sink without a fan attached to it. I am more of a dev than a systems person, but my understanding is that this means that I had a passive heatsink, as an active heat sink has a fan attached to it. (I'm sure that my understanding and definition is an oversimplification of the real difference between active and passive cooling).

I purchased two E5472 Xeon processors, removed the existing processor and heat sink, and installed the new processors into the system (the system was capable of dual processors) and attached two Intel heat sinks with fans that were listed as supporting the E5472 processor (Intel D98510-001 SKT771 Cooler For Quad-Core XEON). Again, based on my limited understanding of processor cooling, this means that this cooling solution for the processors is considered an active solution.

Unfortunately, the system now sounds more like a jet plane than ever. Part of the problem is that there were no more PWM connectors so that the motherboard could regulate the speed of the fan, but I think that even if that wasn't a problem it was going to be pretty loud anyway.

I'm going to try to replace the case fans with quieter models, and if anyone has an general brand or product recommendations I'd love any related feedback you may have. However, my primary question is this:

Can I use passive heat sinks only with two new processors and skip having on the processors altogether? If so, do you have any recommendations or can you point me in a direction to find the right model? Also, is there any harm doing this - does it cut the life of the processors, run the risk of overheating, etc., etc.

Again, per my understanding, I think I'm asking if I can just use a passive heat sink solution for these two chips assuming I have all the proper case fans. Ultimately, I'm trying to cut the noise down; I'm using the system as a Hyper-V server with various servers running on it, so it needs to be on 24/7, and it's right in my home office that I share with my wife and would like make things quieter so we can hear the children running around screaming, yelling, fighting, and otherwise being themselves, because that's a much more pleasant noise than the fans... :D

Any help or recommendations is very much appreciated. Thank you. - Jay

Thank you for your response. I do have the heat sink riser shroud already installed in the system. It covers the memory, memory fan, and the two processors. I'll look tonight to see if the the way it's set up focuses one of the side fans right over the processor. If that is the case, then I think I'd be okay to just use the original heat sink and another matching one.

I'll update this post with further details as I complete these project. Thank you again.

migrated from serverfault.com Oct 25 '12 at 15:35

This question came from our site for system and network administrators.

  • Hi Jay! It seems you've lost your account. Please register your account on serverfault.com, then come back here and log in. You should then be able to comment on your own posts, edit them, accept answers, et cetera. – slhck Oct 25 '12 at 18:49
  • I'm not sure what happened... at this point I've associated my account with google about four times. Hopefully I'm all set now. – Jay Taplin Oct 26 '12 at 14:26

If the old CPU had a passive heat sink then the case must have been designed to channel cool air across that heat sink. On a system with two CPU sockets it is likely designed to channel air past both processor sockets.

All of this means that you can probably call Dell and order two heat sinks for your T7400. If Dell asks a high price then check ebay and similar sites for a Dell Precision T7400 heat sink and riser shroud .


I just checked http://ark.intel.com/. It seems that the E5405 has a max TPD of 80 Watt and the 5472's have a max TPD of 120 Watt. (See this link for the comparison).

That means the heat sink on your original CPU is guaranteed to be able to cool a 80 Watt CPU. I suspect that this is the same heat sink used for all CPU's, but you might want to check that before running a 120 Watt CPU attached to it. (To be fair, I suspect that this is no problem.)

  • See update to question, user seems to have lost their account. – slhck Oct 25 '12 at 18:49
  • Thank you for that information! I'm definitely out of my league when it comes to this type of stuff. I'll verify the wattage on that heat sink - I just ordered two new ones of the same kind, so I hope they work that way! Thanks for your further consideration on this. – Jay Taplin Oct 26 '12 at 14:27
  • You are welcome. Note that you are probably payed more than market average when you bought a Dell. On the flip side a workstation Dell comes with at least 3 years next day repairs, and their professional phone help is quite good. (Professional help as in the people who help corporations. Almost all private person calls to them got botched). Still, if you are not sure about something it does not hurt to phone them and ask questions. I suspect that for a workstation like the T7400 you will get the good people on the phone. – Hennes Oct 26 '12 at 14:32
  • Again, thank you! I will post more information when I receive the two new heat sinks. I do agree about the price - Dell can be very expensive, but I've had really good experiences with their systems in a corporate environment, and so decided to stick with "what I know" for my own small business. Thanks again! – Jay Taplin Oct 30 '12 at 13:15
  • I have installed the two new passive heat sinks and everything is working great! Thanks again for your information. – Jay Taplin Nov 5 '12 at 16:21

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