Semi-passive PSU effectively fanless in a 160W machine?

PSUs: The source of DC power for all components in the PC & often a big noise source.

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resistante
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Semi-passive PSU effectively fanless in a 160W machine?

Post by resistante » Mon Oct 08, 2018 3:12 am

I'm looking for a semi-passive PSU that I can be sure will always stay fanless in my machine. The machine will be sometimes running without any fans, so PSU's temp may be higher than with fans.

The most power hungry it can ever get is this:
Pentium G 54W
2xDDR3
4x3.5" HDD
1x140mm, 2x80mm fans
mini-ITX mobo

I'm looking at cheaper brands like Corsair, Fractal Design, Cooler Master mostly. Also Enermax, Antec, Tacens. Older models are good as they sometimes are of sales for significantly less, things like Corsair TX, RM, HX, Fractal Newton R3, Seasonic SS-650KM.

At what temp are seasonic's fans turning on?

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Re: Semi-passive PSU effectively fanless in a 160W machine?

Post by NeilBlanchard » Mon Oct 08, 2018 3:55 am

The case and set up are going to be key - what are you planning?

resistante
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Joined: Wed Jan 24, 2018 6:28 am

Re: Semi-passive PSU effectively fanless in a 160W machine?

Post by resistante » Mon Oct 08, 2018 4:26 am

The case is Cooler Master Elite 110. Sometimes with a fan or two, sometimes without any, even on the CPU, if Celeron G will be used, I'll put Arctic Passive (or another passive heatsink if there are any you recommend) on it.

Use case: NAS, ZFS, occasional extremely heavy torrenting.

Abula
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Re: Semi-passive PSU effectively fanless in a 160W machine?

Post by Abula » Mon Oct 08, 2018 6:03 am

resistante wrote:At what temp are seasonic's fans turning on?
It depends on the PSU, not all are temp driven, some are load driven, and some have both, and even then you cant generalized on all seasonic psu, some might be design to start before and others after.

I recently bought a Seasonic Focus Platinum 550, and with 8700K on prime95 never saw the fan spin up, thats about 150W load which should be less than what your setup will reach.

I would think for a less expensive PSU the CORSAIR RM550x, but you do go into a full sized atx, while the seasonic is 140mm that might help on a tight case.

Now there are also SFX PSU, like the Corsair SF450, that should be fanless up to some point, probably wont start with your load, but i dont own it to say for sure. And if you were to go fully fanless on the PSU, SilverStone SST-NJ450-SXL but its an expensive psu, on either you will need a bracket to mount them, like SilverStone PP08B

Another option could be a picoPSU, you can get 150XT with 150W brick that would be fanless.

Be carefull with 3.5 hdds on fully fanless setup, on my server with low rpm fans they do go above 40C, without fans i would think they would go above 50C, specially on a raid environment where all your drives will be access.

resistante
Posts: 34
Joined: Wed Jan 24, 2018 6:28 am

Re: Semi-passive PSU effectively fanless in a 160W machine?

Post by resistante » Mon Oct 08, 2018 8:36 am

Will CORSAIR RM550x or its older version RM550 be fully fanless in my system? I couldn't find any info on when the fan turns on in it... Even 20% * 550W is just 110W.

Full ATX will probably be cheaper though.

Does this picoPSU come with a power brick with efficiency level V? No info on that. And how do I attach its DC-in cable to the case so that it fall into the case the moment I try to plug in cable and looks right?

Abula
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Re: Semi-passive PSU effectively fanless in a 160W machine?

Post by Abula » Mon Oct 08, 2018 10:51 am

resistante wrote:Will CORSAIR RM550x or its older version RM550 be fully fanless in my system? I couldn't find any info on when the fan turns on in it... Even 20% * 550W is just 110W.
Its very likely, but i cant say for sure, also remember some turn their fans on load and some on load, and some have both, so in a fanless setup heat could get into levels where it might turn on, its hard to predict on each, the only way would be to really buy a fanless.
resistante wrote:Full ATX will probably be cheaper though.
Its very likely, but really depends on each, there are ATX that cost $500.
resistante wrote:Does this picoPSU come with a power brick with efficiency level V? No info on that.
Yes there is info on that, you simply need to search for the brick. 150w AC-DC Power Adapter, 12v 12.5A ---> "High efficiency, level VI". In case you want higher than 150W, then also look for the 192w AC-DC Power Adapter, 12v 16A ---> "High efficiency, level VI".
resistante wrote:And how do I attach its DC-in cable to the case so that it fall into the case the moment I try to plug in cable and looks right?
This is something you need to decide, there are lots of ways to do this, my suggestion is do a acrilic PSU cover, and on that drill the plug, this way you are not permanatly modding a part of the case, but this is something that you will need to decide upon building.

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