Which CPU for passively cooled computer?

C

coolpurplefan

Gawd
Joined
Feb 19, 2006
Messages
547
I'm at a point where my ears seem to be ringing any time I'm exposed to noise and I've had it. I'm thinking of going totally passive. So, I found Seasonic makes a passively cooled power supply, Asus makes a couple of passively cooled video cards and I think I could always use an solid state drive as well. At first I thought it might be cool and funny to just get a mini ITX with a built-in CPU and passive heatsink and go caseless. But, I'm now considering taking my desktop Silverstone case and converting it instead of selling it.

So, is it worth it to try to get a mobile processor? Then I might have a challenge trying to find a motherboard. Plus, if I get a mini ITX motherboard, I'm not sure if the video card slot will align with the desktop case.

If I get a desktop processor, is there any available that will allow me to use a Scythe mini ninja without having a fan next to it?
 
i3-2120T @ 35W or if that's not enough processing power try an i5-2405S @ 65W. Might even be able to undervolt them a bit more for even less heat, esp if they'll rarely run full bore, instead of that scythe mini you could maybe use something like this with no fan or even go all out and get something crazy like a NH-D14 and just take off the fans, probably more than enough surface area to cool 65W max TDP CPU without the fans. Another option would be to get a H80 or H100 and mount them at the top of the case, again without fans, if the pump motor for those is still too much sound for you then you'll likely get annoyed by the constant buzzing of bits flipping in your RAM.
 
sandy bridge runs pretty cool... if you undervolt or get the low-tdp versions, you definitely won't need a case fan

have you seen the stock hsf for the low powered hsf?

brb finding pics

EDIT: i3 2100 hsf vs i3-2100T... top of the HSF is 1-7/16" (37mm) for the T version

http://www.missingremote.com/blog/intel-i3-2100t-and-i3-2100-heatsink-and-fan-differences

bQAJWl.jpg
 
Last edited:
have a friend with on 2600k using a gemini 2 heatsink modified plate so it would work with the lga 1155 socket the big one that can take 2 120mm fans next to each other. No oc on his cpu and runs everything he throws at it with no running fans
 
Oooooooooooh, so the Intel i3-2100T and i3-2120T are 35w. So, is there a chance a Scythe Mini Ninja would cool it with no fan or should I just go for a larger model?
 
If you only criteria is a passively cooled computer you can get an Intel Atom mini ITX with CPU
 
Hmm, we really need to know your processing requirements. If you don't have any, then just get a passively cooled Atom board in a tiny case. Otherwise, designs will need to be made to accommodate :)

One option is to simply have the computer in another room, and run leads for interface+sound into your room.
 
RealityCrunch said:
Hmm, we really need to know your processing requirements. If you don't have any, then just get a passively cooled Atom board in a tiny case. Otherwise, designs will need to be made to accommodate :)

One option is to simply have the computer in another room, and run leads for interface+sound into your room.
Click to expand...

It's a tough call since the i3 2120T seems like a reasonable processor. But, my initial idea would be to have just an Internet browser. However, I figured if I shut off my other computers if this machine was on, then I might want it to be powerful enough to do more anyway.

Ah, decisions, decisions. Besides, for whatever reason, I did temporarilly see some Atom motherboards with CPUs and now I can't find them. I know I'm going to check but just in case the i3 has built in video like the the AMD APUs, do you think it's compatible to have a video card on the motherboard at the same time as the i3?

By the way, I live in what they call a "loft" in Quebec. In other words, it's just one very long room that's like an appartment.
 
Yes you can use a separate videocard with the I3, as well all the I3's have onboard graphics other then the the I3 2125.
 
G620T, i3 2100T and i5 2390T are all 35W dual cores; the OEM i5 also has Turbo Boost.

i5 2500T is a 45W quad core. Alternatively, get the Supermicro X9SCV-Q and stick a mobile CPU in it.
 
I've got a core2duo E6550 running the stock heatsink with the fan removed and there are no case fans in the case at all. It works perfectly fine and doesn't overheat, I'd imagine most of the newer stuff will be fine.
 
coolpurplefan said:
Oooooooooooh, so the Intel i3-2100T and i3-2120T are 35w. So, is there a chance a Scythe Mini Ninja would cool it with no fan or should I just go for a larger model?
Click to expand...

Thats the TDP which is the maximum wattage the CPU package is designed for. the actual wattage is even less.
 
It would be much more logical to just have fans that move so slow you can't hear them. Then your options are almost limitless. Especially with a huge heatsinks.

There is no reason to completely remove fans from your system, a slow enough fan will not be audible. two slow high-quality 120mm fans on case, two large heatsinks for gpu/cpu with a just incase fan on cpu cooler controlled by software and you or any other human, won't be able to hear it.


Also, its usually a better option to skip the ready-made passive gpus and just get a gpu + huge-heatsink.
 
Last edited:
100inch said:
It would be much more logical to just have fans that move so slow you can't hear them. Then your options are almost limitless. Especially with a huge heatsinks.

There is no reason to completely remove fans from your system, a slow enough fan will not be audible. two slow high-quality 120mm fans on case, two large heatsinks for gpu/cpu with a just incase fan on cpu cooler controlled by software and you or any other human, won't be able to hear it.


Also, its usually a better option to skip the ready-made passive gpus and just get a gpu + huge-heatsink.
Click to expand...

Well, I've tried two different fan controlers with different fans but I find the fans cut off completely under a certain point. I don't know if this is due to the fans or the fan controlers. I guess finding fans that can go real slow might be the trick.

EDIT: My first choice though would be to go completely passive.
 
Last edited:
You could try something like THIS. Then you could use whatever CPU you want and probably a midrange GPU in the loop as well.
 
KarsusTG said:
You could try something like THIS. Then you could use whatever CPU you want and probably a midrange GPU in the loop as well.
Click to expand...

Yeah, I read the pump for water cooling will make noise as well. In other words, I was thinking of building a machine with an SSD instead of a HD.
 
http://www.silentpcreview.com/Serenity_i7_Sandy_Bridge_PC

That will certainly help. It's almost silent when idle (SPCR has a sound floor of 10 dBA) and extremely quiet under load: 11 dBA idle, 12.5 dBA Prime95 + Furmark. Thus passive is overrated; with a well designed case, with good fans and some basic airflow knowledge you can make a silent computer; even SPCR only needs a completely silent computer for the one in the anechoic chamber that drives all the equipment: http://www.silentpcreview.com/Silent_PC_with_No_Moving_Parts
 
I measured this over the holiday:
2500K @ 2.2GHz, 0.9v = 0.9W idle, 21W Prime95

I could probably entirely remove the fan from the Hyper 212 Evo at those settings. (But that's not my normal settings, just testing.) Though I agree with Radical 2 posts down, personally I'd still keep a silent slow fan running.

Also, those TDP ratings are exactly that -- a rating. You'd have to take a measurement, which is not the easiest thing. (I have a custom setup.)
 
Last edited:
I've tried passive, and I've found that having 1 or 2 undervolted fans is a better choice. This amount of airflow can have a HUGE effect with only a very small amount of added noise (if it's even audible from outside the case). If you want to see if this would work for you, just buy 1 or 2 quiet fans and run them undervolted outside of a case (or inside a spare case if you have one). If this amount of noise bothers you, THEN look into a passive system.
 
Radical said:
I've tried passive, and I've found that having 1 or 2 undervolted fans is a better choice. This amount of airflow can have a HUGE effect with only a very small amount of added noise (if it's even audible from outside the case). If you want to see if this would work for you, just buy 1 or 2 quiet fans and run them undervolted outside of a case (or inside a spare case if you have one). If this amount of noise bothers you, THEN look into a passive system.
Click to expand...

Fact is I already have a computer with three Nexus 120mm fans and a Nexus 92mm fan on a fan controller and it still makes a little more noise than I'd like. And this is with a Fortron Blue Storm II power supply.

I may have made a mistake in buying the Nexus fans though because I suspect they're the ones that only work at one speed. So, which ones do you find can work at slower speeds?
 
Good suggestions if you dont want to wait for Ivy Bridge cpu's and 28nm GPU's.
 
coolpurplefan said:
Fact is I already have a computer with three Nexus 120mm fans and a Nexus 92mm fan on a fan controller and it still makes a little more noise than I'd like. And this is with a Fortron Blue Storm II power supply.

I may have made a mistake in buying the Nexus fans though because I suspect they're the ones that only work at one speed. So, which ones do you find can work at slower speeds?
Click to expand...

I think those Nexus fans are supposed to be really quiet, though I've never used them, so maybe it looks like passive is for you after all.
 
Search around, two decent 120mm fans at low speeds will not be heard/measurable at 6 feet in most rooms. Keep the case clean and wires in proper places. You don't need 4 fans. Stick with one or two. If the air is going in different directions, hitting air from other fans, itll create noise. Ideally it should have a straight pathway out the case or into another fan going in the opposite direction and they'd be screwed onto a solid metal piece or dampened with rubber. Usually one 120mm in the back is fine if the heatsinks are big enough. or one blowing out in the back and one blowing in in the front.

If it control the voltage lineally rather than pwm it will stall fans at low enough speeds. What voltage are they getting before they stall?
 
Last edited:
100inch said:
If it control the voltage lineally rather than pwm it will stall fans at low enough speeds. What voltage are they getting before they stall?
Click to expand...

I don't know exactly. I know it's when the fans are at around 4 on the fan controller.

I would still like to see if I can make a totally passive one. One of the reasons of course would be to test various fans anyway. I know silentpcreview is out there, but different fans make different sounds. And you can't see that by looking at decibels.
 
Most decent fans handle a very low RPM properly fed without making weird noises. Once you get low enough RPM the db should drop below room noise unless your PC is on your desk next your your ear (and even then). So you won't hear anything. If you are in a room near 15db you are creepy, spent a lot of money, and you wouldn't like it. Its kinda tough for sites to measure accurately fan noise at low RPM because some measure with an ambient room noise that is pretty high so lower RPMs will blend because they are below room noise.
 
Last edited:
What do you need this thing to do? HERE is a board simlar to what I built my file server on. I setup windows 7 on it first to tool around and it was supprisingly peppy. You could probably do some light gaming on it, especially if you tossed in a midrange card, which is all your going to have completlely passive non water cooled anyway. HERE is a review on it and some similar boards.

Oh, HERE is some sound dampening material. You are going to want a pack for your case for the fans you do put in there. I do recommend the Noctua fans. The fugly coffee colored ones since they are crazy quite.
 
Last edited:
KarsusTG said:
What do you need this thing to do? HERE is a board simlar to what I built my file server on. I setup windows 7 on it first to tool around and it was supprisingly peppy. You could probably do some light gaming on it, especially if you tossed in a midrange card, which is all your going to have completlely passive non water cooled anyway. HERE is a review on it and some similar boards.

Oh, HERE is some sound dampening material. You are going to want a pack for your case for the fans you do put in there. I do recommend the Noctua fans. The fugly coffee colored ones since they are crazy quite.
Click to expand...

Thanks for the name of a good fan. Anyway, just saying though that when you put HERE on a link when the link goes dead then people reading old threads won't see what you were talking about. Thanks everyone for the comments.

It's kind of interesting though that I read on Anandtech that HTPC fans prefer Nvidia video cards but Nvidia did not let manufacturers downclock their 500 series GPU. So, the most powerful passive Nvidia card is apparently a downclocked GTS 450.

I casually wonder if I went for a mini ITX motherboard that if the I/O shield would not align with my Silverstone LC20 case.
 
You must log in or register to reply here.
Back
Top