Running a CPU entirely passive

[the pokemon kid]

Hi All,

I am putting together a PFSense router together. I have got a Intel 4130t which I am using as the processor. This processor has a thermal disopation of just 35w!

The whole system is going into a 1u server case which will eventually be rack mounted along with my NAS. This rack will be on the other side of the room in my office.

I bought one of these 1u turbine style fans to go into the system and it is kicking out a lot of noise! So I would like to find out if I could buy a Noctua L-9i cooler, take the fan off and run it entirely passive. When I mean entirely passive I mean; no fans in the system at all. I wouldn't be able to fit the fan on the Noctua as the case is just too short to support it.

The system at no stage will be under any load as it will be running as a PFSense router on a small network.

[FloRolf]

I wouldn't do that in a 1U.

In a real tower and some Noctua NH-D15 I wouldn't see an issue but not like that on something that has to run reliably 24/7

[aisle9]

I doubt anything that would fit in a 1U rack could passively cool even a 35W CPU. Even if you aren't putting it under load, it will put itself under load for updates, etc., and that will throttle and/or BSOD it.

 

If entirely passive is your thing, consider an all-in-one ITX board with something like an Atom, mobile Celeron or Pentium-J. Those sub-10W CPUs would be fine, though I'm not sure how they'd do on ability to run your server.

[Labeled]

Probably advise against it, however if you want to test it out post your results.

without airflow through the system I doubt it would be ok, so I'm not sure if you mean just no fan on the cooler it self or no fans in the case entirely.

[Guest]

I found something called Dynatron K129. It's a 1u formfactor and according to the manufacturer it is rated for 95W TDP but I don't know if it relies on case airflow or not.

Nvm it relies on case airflow from server fans

[SupaKomputa]

you need some sort of airflow for passive heatsink, or it will just warm the air surround it.

[germgoatz]

just cut a hole in the case and add a good filter

[Labeled]

if you can disable hyper threading, and get decent airflow through the case you might be fine. Passive cooling doesn't work in small spaces without natural circulation. even if its not producing much heat it will end up creeping into unsafe levels without air. intel's TDP isn't really trustworthy anyway.

 

Actually, Noctua has some 1U fans. https://www.newegg.com/Product/Product.aspx?Item=9SIAADY5U14594&Description=1u fan&cm_re=1u_fan-_-1YF-000T-00093-_-Product

 

[X_X]

FWIW I had a plain 4130 that would undervolt by more than 200mV @2.7GHz and run CBR15 at that with less than 7W. IOW you can cut down the power if you put a little work into it.

[the pokemon kid]

Just as an update, I decided to get a really small CPU cooler from Silverstone. Its one that they market as a upgrade to the stock Intel cooler. However it is running whisper silent now. The only thing that is actually making noise in the whole machine is now the power supplies fan...

[X_X]

@the pokemon kid What power draw do you get (HWiNFO sensors) at 2.9GHz with CBR15?