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View Full Version : PASSIVE PC Cooling rant



Paul.Cov
14-01-2009, 09:06 PM
Hello all,

This is not so much an enquiry, rather an invitation to discuss the issue.

PC cooling has been to the fore in my mind lately, thanks to the temptation to upgrade my gaming hardware (and a lack of cash holding me back).

A bit of a browse around the AMD boards revealled that my many years old AMD 2200+ was running hotter than recommended (and has been since I built it), which left me wondering what sort of crazy lenghts I'd have to go to to keep the likes of an AMD X4 Phenom cooled. (let's not diverge to Intel vs AMD, and besides, I do not believe the performance vs power vs software for multicores equation makes it a good time to upgrade anyhow... this is just about cooling at this stage)

Frankly, I've thought for years that the fan arrangements inside PC's were nuts, and I don't know whether to laugh or cry when I hear of PC's with 5+ fans inside them... some pushing air in, some pulling air out, and a bunch just moving hot air around inside... turning the entire case into a heat radiator and a noise source.

So I simply left the side off my gaming case, and got an immediate 10 degree drop in CPU and System temps.

Fan noise seems no worse than before (GPU, CPU, PSU fans and added case fan)

By leaving the side off I've almost removed the relevance of the case fan and PSU fan. They moved sod-all air anyway, and I've got a 10 degree improvement in the middle of a stinking hot summer.

So, at the risk of upsetting people, why not put a grille over the side of the case (to keep kids, pets and people safe / the PC safe from them) and let a whole bunch of free, silent, passive airflow do the job of a whole bunch of fans?

This experience has got me wondering if a BIG passive (fanless) heatsink for the CPU (with loads of area open to the air) would be ok for anything less than a major gaming rig (GPU still fanned due to it's confined space).

The other advantage of this (besides noise, heat and power) is to do with dust!

Traditional arrangements have all fans extracting air (yeah, I know that's a subject all on it's own), and all inflowing air is getting in through grilles (if any exist), gaps in the case seams, floppy drives, optical drives, and all those poorly sealed PCI slots on the rear.

I've had many a FDD die through years worth of dust sucked into them between those occasional uses (at which time their dust laden heads destroy any floppy media as well).
I suspect dust sucked in had killed my first CD burner too (back in the days when, sadly, they cost heaps)

With a passive cooling system the dust will be more widely dispersed OUTSIDE components, rather than concentrated inside components and on the PSU fan and vents, the drives.

Dunno what to conclude really, but I'm thinking that a modern system with a PSU with 2 fans, a case fan, a GPU fan, a northbridge fan, a RAM fan, a CPU fan, a HDD fan, and a few more fans to add to the insanity is just totally nuts!
Why plumb in a garden hose to cool it all when removing the lid or side will do just as well?

Anybody else with experience of 'open' cases and the combination of heat and dust on those systems?

TIA.

Paul

Metla
14-01-2009, 09:10 PM
No sides on my case. Thats cause Im lazy.

Nor do I care how hot its running.

If it ever hit the thermal shut-down limit then perhaps I'd look into it, till then, not a problem.

2200 Athlons always ran a bit hot, and the motherboard temp sensors are pretty much worthless.

qazwsxokmijn
14-01-2009, 09:20 PM
I've got 12 fans in total in my case and I ain't complaining. ;)

tweak'e
14-01-2009, 10:00 PM
if opening case makes temps go down then you have a case air flow problem.
ditto with dust in floppy drive, that means fron air vent is to small.

you can run an open sided case with no case fans (cpu/gpu is a different story) easy enough. just got to watch you don't get dead spots where air doesn't move and will heat up very high. it may mean part of the motherboard/hardrive etc overheats and dies.

memphis
15-01-2009, 01:05 AM
Wow you really need a new modern case that has proper airflow and cooling!!!

Whats your problem with having fans to cool your component's so they dont cook and overheat and have problems or die?

You can get a PSU with 1 x 120mm fan or a PSU with 1 x 140mm fan.

CPU you can get huge heatsinks that will do the job without a fan but for gaming or other intense cpu usage then a hsf would be reccommended.Have a look at the THERMALRIGHT ULTRA-120 EXTREME for an example.

Northbridge:dont need a fan if your motherboard has a passave heatsink on it allready.Or you called check out:THERMALRIGHT HR-05 CHIPSET COOLER or THERMALRIGHT HR-05 SLI / IFX

GPU:check this out:THERMALRIGHT HR-03 GT EXTREME VGA COOLER NO FAN - (But I would put a fan on if it was going to be used for gaming or other intense stuff).

Ram:you dont need a fan on them if you really have to you can get THERMALRIGHT HR-07 MEMORY HEATSINK

Harddrives:ZALMAN HEAT PIPE HARD DRIVE COOLER and there are other brands that do passive cooling of harddrives as well.

So with all that done thats only one fan in total for the whole computer being the psu using 1 x 120mm fan or a psu using 1 x 140mm fan.

However personaly I would want 1 x 120mm case fan or bigger to cool my harddrives as it is best to keep them under 40 c for stability and long life of them etc.

So that could be two fans in total for a computer.

Would that computer get hot?

Depends:
Case size:
Small case no way would I use that it would get too hot.-(not enough passive airflow and space).

Mid size case depends on the space as well,how close is the harddrives to the graphics card,will they be close by to each other and heat each other?

Full tower would be a better case if doing passive cooling on all your componets because being big you have more space and therefore more passive cooling can take place.

Where the case is going to be placed on the ground on carpet,in the sun on a bench etc.

NO dont do that,put it on a desk,bench near a window if you want but with a curtain closed so you are not getting the heat from the sun etc.,your computer can heat itself you dont need to help it with that!!!

Would I do any of this myself?
Depends what I would be using the computer for.

Gaming computer:No way!!!As many fans as I want to keep it all cool from all the heat generated from spending hours playing games.Noise from the fan's,use a fan controller and use headphones or speakers so it does not matter.

Lounge/Multmedia computer:Yes as long as it is for movies/music/internet etc.,and no gaming.-(I would get a 1 x 120mm fan hooked up to a fan controler to cool my harddrives).

Download/P2P/file server/ etc. going 24/7.:Yes,but I would have 1 x 120mm fan hooked up to a fan controller to cool the harddrives as they would be working all the time.

gary67
15-01-2009, 05:40 AM
Go for water cooling if fans are too noisy

Chilling_Silence
15-01-2009, 06:36 AM
Ive got a desk fan sitting there the whole time aimed at my PC ... mistakingly purchased a passively cooled GPU, that was a bad idea ...

wratterus
15-01-2009, 07:36 AM
I have a lot of fans....and water cooling... its not super quiet, but my lightly OC'd CPU runs at 35 degrees...

Bear in mind this isn't actually my PC, but its the same case.

Blam
15-01-2009, 08:05 AM
Nice case you got there wratterus...is this you next upgrade?:

Chilling_Silence
15-01-2009, 08:07 AM
Now that looks niiiiiiiice! :D

pctek
15-01-2009, 08:18 AM
A bit of a browse around the AMD boards revealled that my many years old AMD 2200+ was running hotter than recommended which left me wondering what sort of crazy lenghts I'd have to go to to keep the likes of an AMD X4 Phenom cooled.

I don't know whether to laugh or cry when I hear of PC's with 5+ fans inside them... some pushing air in, some pulling air out, and a bunch just moving hot air around inside...

So I simply left the side off my gaming case, and got an immediate 10 degree drop in CPU and System temps.


why not put a grille over the side of the case and let a whole bunch of free, silent, passive airflow do the job of a whole bunch of fans?

This experience has got me wondering if a BIG passive (fanless) heatsink for the CPU would be ok for anything less than a major gaming rig
Once upon a time CPUs only had little wee fans over them without whacking big heatsinks and large fans.
But then they kept on adding more and more transistors. More hardware in a smaller space.
You can look up the physics of this.

Older AMDs did run hot. SO? It wasn't too hot or it would have long since died.

Motherboards these days will shut down if they detect a too hot CPU and/or give warning beeps.

You cannot have fanless cooling now, AMD or Intel. Unless you want to fry it.

Case fans produce airflow. At least they do if set up correctly. The idea is to have it suck in air from the front and expel it at the back.

Just having a grill isn't going to cause any airflow at all unless you have it outdoors in the wind.

Also you should use a roomy case for gaming PCs, little HT cubes won't do.

I think you don't really understand the principles of it.

wratterus
15-01-2009, 08:33 AM
Nice case you got there wratterus...is this you next upgrade?:

I think that's too risky for my setup. Not very desk friendly, can't put stubbies on the top of it. :p

Blam
15-01-2009, 08:50 AM
I think that's too risky for my setup. Not very desk friendly, can't put stubbies on the top of it. :p

:lol:

I'm sure you could find a away....:illogical

Chilling_Silence
15-01-2009, 09:00 AM
Once upon a time CPUs only had little wee fans over them without whacking big heatsinks and large fans.
<snip>
You cannot have fanless cooling now, AMD or Intel. Unless you want to fry it.

I know Im nit-picking here, but if you look at the attached pic, you'll see the CPU is the one with the smaller heatsink & no fan. I believe its the northbridge under the massive heatsink / fan!
Also, I use a fair amount of AMD Geode CPU's, increasingly more-so, and they have no heatsink at all ;)

dugimodo
15-01-2009, 09:45 AM
I'd agree there seem to be a crazy amount of fans in computers these days. Passive cooling would absolutely be possible but would need to be very well designed to work properly which would be next to impossible with systems cobbled together from parts built by multiple suppliers. Manufacturers take the safe option and throw a fan on.

My old gaming case is nothing special (a thermaltake swing with 2 12cm fans) but some sensors actually heat up when I remove the side, an indication of fairly good airflow. I often wonder why more cases don't take air out nearer the top - we all know hot air rises.

Oh and my new gaming machine is built in a cheap small cube style case and has no problems with overheating, a single rear 12cm fan with 79cfm does the trick. You just need to chose your case and hardware to suit each other when going compact.

SolMiester
15-01-2009, 10:31 AM
I know Im nit-picking here, but if you look at the attached pic, you'll see the CPU is the one with the smaller heatsink & no fan. I believe its the northbridge under the massive heatsink / fan!
Also, I use a fair amount of AMD Geode CPU's, increasingly more-so, and they have no heatsink at all ;)

Err, are you sure about that?....why would a north bridge require such a big HSF while the cpu doesnt?. I have check several of the mobo, and none appears to have the HSF on the NB?

Chilling_Silence
15-01-2009, 10:48 AM
Not on the D945GCLF or D945GCLF2 motherboards I have:
http://www.upgraderguides.com/index.php?type=&id=233&page=2

Sorry, I should have clarified I was talking about the Atom boards in particular :)

SolMiester
15-01-2009, 11:21 AM
Do those boards come with the atom already installed chilli?....what are you using them for?

Chilling_Silence
15-01-2009, 12:04 PM
Yup! You can only get them as the mobo / CPU combo.

Im using them for *heaps*! Very cost-effective little suckers, and that was why I was asking in the other thread about their power consumption.
I use them for:
General Desktop computers
The dual-core for a Media Center PC
But primarily Im using them as VoIP PBX servers.

Brilliant little boards, though if your Northbridge fan fails, it gets *incredibly* hot. It even corrupted the data on a CF card at one point. Now Ive got 24/7 monitoring with SMS alerts etc in-place that keeps an eye on that kind of thing. You could fart near a PBX and I'd probably know about it ;)

Chilling_Silence
15-01-2009, 12:31 PM
You used any yourself?

MAC_H8ER
15-01-2009, 12:39 PM
one intake fan and 2 exhaust inculding PSU fan for me

a mate of mine went fan berko once cause he was anal about overclocking

turns out the load of the fansa blew up the PSU before he could even think about tweaking it

idiots and neon case fans eh?

also remember working on an early model Dell with a 3.2GHZ dual Core Pressie CPU

the heatsink was as big as my fat head!

Silver_Blade
15-01-2009, 02:42 PM
I have a Zalman 8700 HSF on my cpu while its overclocked to 3.6Ghz from 3 (E8400) it runs at idle with only 30 degrees. my case only has one intake (120mm) one side intake (custom) one back exhaust (120mm) thats all apart from a corsair psu fan blowing down into case and out the back.
4870x2 is cooled by the front intake fan as i use the 2nd sli slot as it was below all my HDD and in front of the intake fan:banana