CPU Cooling Problems (120mm vs 240mm vs 360mm vs Intake/Exhaust)

Subressor · Mar 7, 2016

Hi All,

TL;DR - I'm buying a new case. I want water cooling. I want to overclock. What's the best setup with the given intakes/exhausts?

Not TL;DR - Curious question, maybe someone much more knowledgeable than me can answer. I am treating myself (yay birthdays!) and buying a Lian LI PC-08 Case

http://www.lian-li.com/en/dt_portfolio/pc-o8/

I'm getting a 5820K and I want to go for water cooling (because overclocking and swag). However.... I'm stuck. There are the following ways to install an all-in-one water cooler:

240mm Filtered Intake (compartment 1) > Hot air would run over CPU, Mobo & GPU before being blown out by a 120mm fan

120mm Unfiltered outlet (compartment 2) > Hot air would come from the CPU, Mobo & GPU and pass out

360mm Filtered Intake (compartment 2) > Hot air would run over the wires, PSU and HDDs before being exhaled by a 240mm exhaust.

(DIY/breaking possible) 240mm Unfiltered outlet (compartment 2) > Air from the wires, PSU and HDDs would go and exhaust out, but I would have to do some serious DIY damage to the case lol. Namely, find a new place for the HDD bay and find a way to make the cooling pipes stretch.

Common sense tells me not to put a radiator on an intake because it would heat up the air inside of the case, causing long term damage/degredation to the components inside. But I've only got a 120mm exhaust for the main chamber to mount a radiator. There is the possbility of installing a 240mm where the hardrive bays are, but without some serious DIY (or an extra-long hose) the case wasn't designed for that. The case will have 2 980Ti's in it EVENTUALLY.

What would you do? Does hot air over the wires/PSU/HDDs matter? Should I go balls deep on a 360mm radiator? Or a 120mm radiator on the exhaust? Or a 240mm on the above intake?

Thanks

Ryan_78 · Mar 7, 2016

Most commonly we see the 240 mm on the top exhaust. The 120mm can be equally good as a 120 or 140 tower cooler, so it is not really worthwhile to invest in them. A 240 on the exhaust will pull in air from around the case and blow them out, creating a better situation. The top of the case supports the 240, without need to rip out, as specified in the description of the case. The front will have a 3 120 mm fan to bring in cool air which will cool th,e components. The top will have a 240mm 54 mm thick radiator to exhaust the air and cool the CPU. The back will have one exhaust. This will be my optimal cooling solution.

Subressor · Mar 7, 2016

Ryan_78 :

Sorry for the lack of clarification - the top vent is filtered, so I wanted to use it as an intake into the main chamber with the CPU/Mobo/GPU. I assumed it was either use it to pull air in or nothing. I guess I can exhale using the top, but is that a good idea?

jmsellars1 · Mar 7, 2016

On my phone so only a short reply for now but putting the rad on an intake will give the best CPU temps but higher mobo/GPU temps. An exhaust rad would do the opposite, higher CPU temps but lower GPU/mobo. I'll have a closer look at that case when I get chance and suggest something more specific.

jmsellars1 · Mar 7, 2016

Looks like the case is specifically designed to have the radiator in the front, it has a separate chamber so it won't affect your GPU/Mobo temps. A 120mm rad probably won't cut it, rule of thumb is 10mm of radiator for each 10W of heat and even at stock the 5820k is like 140W or something. A 120mm would probably be fine for stock settings but it wouldn't be quiet. A 240mm set up as an intake would be a good price/performance option, have 4 fans on it and set them up as push pull and that would be great. 360mm would probably be a bit overkill but the advantage of that is that it might stay very quiet under load if you choose good fans and control them properly.

Ryan_78 · Mar 7, 2016

So really it's the exhaust system that has to be efficient. Use the front for radiator
Make sure the extra heat can easily dissipate.

Subressor · Mar 8, 2016

jmsellars1 :

Thanks for the detailed response all!

@j sounds good! I was worried though if the wires ever touched the actual radiator or get heated up would cause any long term problems. as the air from the front main intake would go directly over the mess of wires. I'm over clocking my GPU so I think using the main chamber is not an option. If I put it on the intake; the GPU would heat up. If I put it on the outlet, it would be noisy as he'll.

jmsellars1 · Mar 8, 2016

No, the radiator won't get hot enough to burn or melt anything. The CPU would shut the whole system down before it got anywhere near that point.

I'd put the rad on the front intake, it has its own chamber then and won't affect GPU temps. I think 240mm set up as push/pull would be best in terms of cooling. A 360mm with just push fans would be nice for quietness but probably more expensive.

Subressor · Mar 8, 2016

Thanks

I think for quietness I'll go for a 360mm radiator and stick that next to the front intake in chamber 2. I was worried it would get to ~50C or so under load and start cooking the wires, but if you are happy that having hot CPU air blowing straight onto the wires wouldn't damage anything long term I'll take it

jmsellars1 · Mar 9, 2016

50c under load is very very cool, anything under 70c is fine. Honestly even if the CPU hits 90c you're not going to damage the wires.

Subressor · Mar 9, 2016

What!? Surely if the cpu hit 90C, and hence the radiator got to 90C, the wires would be f***Ed

jmsellars1 · Mar 9, 2016

Nah it doesn't really work like that. The whole point of a radiator is to have a large surface area to dissipate the heat (spread it out). Even if a CPU gets to 90c, a large radiator like those in a desktop will feel a little bit warm but not too warm to touch, nowhere near in fact. Then the fans blow the heat away from the radiator and dissipate it even more into the air.

Subressor · Mar 9, 2016

Ahhhhhhh... So if I started compiling a video file (CPU intensive) on an overclocked 5820K (4GHz or so) which uses around 140W stock speed (3.3GHz), it would get to say, around, 50C? But the actual temperature of the radiator would reach around 30C to the touch (and maybe the ambient air temperature around the wires 25C)?

jmsellars1 · Mar 9, 2016

It is hard to put an exact number on it but that's the principle yeah.

Subressor · Mar 9, 2016

Thanks

Once I build my rig I'll take some measurements and let you know what numbers I actually get!

Do you have any recommendations for a good mianstream 360mm all-in-one radiator? Can be with/without fans.

envy14tpe · Feb 17, 2017

Curious as to what config you went with? I'm thinking of getting that case.

Subressor · Feb 19, 2017

I went for the 360mm in the end (triton 360) and needed some anti-kink coils. I made a Youtube video which goes into more detail if you're interested

https://www.youtube.com/watch?v=1IB3oW8eZkw

Works very well. I can push the CPU and it takes 5 mins straight of AIDA64 to max it out (though I think it does eventually throttle)

jmsellars1 · Feb 27, 2017

If it is throttling at all something is wrong, I'd expect it to get through 24 hours no problem. Are your fans speeding up under load?

Subressor · Feb 27, 2017

jmsellars1 :

You think? I mean bearing in mind I overclocked the 5820k to 4GHz (25% increase), I think I read somewhere that makes it very thermal inefficient.

Yea both the CPU fans (push) and the case fans behind it (pull) go mental @ 80 Celsius. I think when I broke it in to check how stable the overclock was it hit 95C and I stopped it

jmsellars1 · Mar 21, 2017

Sorry I didn't reply for a while but I'd never expect that to get to 95c at all on a 240mm rad, let alone a 360mm. I'd check that the cooler is seated properly and that the pump is plugged in and set to a fast enough speed.

CPU Cooling Problems (120mm vs 240mm vs 360mm vs Intake/Exhaust)

Honorable

Honorable

Honorable

Splendid

Splendid

Honorable

Honorable

Splendid

Honorable

Splendid

Honorable

Splendid

Honorable

Splendid

Honorable

Champion

Honorable

Splendid

Honorable

Splendid

Share this page