Radiator size for WC

[Kogure]

Hi everyone. I need some help with picking the size of the radiator for my first water cooling. I want to cool an Intel i7-4770 and a GTX 780 (1019 MHz clock). Possibly the chipset later on. Around 350W of TDP (without the chipset).

I should mention that I already read the sticky, but the process of calculating the perfect size is really complicated. Besides, my case can only fit in a slim 2x 140 or a regular 2x 120 ( which will most likely not be enough). So calculations can pretty much go out the window. I decided to go for an overkill radiator and hang it up on the wall somewhere. I have a pretty big budget.

This is where I need help. I can go for a 3/4x 120, 3/4x 140, or a 1/2x 200. Can I have your opinions on the best size out of these? Keep in mind that I would prefer to keep the fan speeds low. Push/pull is also an option.

 

[Drew010]

If you want to keep the fan speeds low, then go with a 4x140 and get Corsair AF140 fans.

 

[oczdude8]

Get 3x 360mm radiotors. You probably wont even need to use fans for that setup LOL.

 

[HEXiT]

what kind of case are you gonna use. do you want a push / pull or just a push fan config.
what brand are you looking at...
http://linustechtips.com/main/topic/1755-water-cooling-101-a-good-place-for-newbies-to-start/ look here for a newbies guide to water cooling. it has lots of info as well as some easy to follow video
normally i dont link to other sites but this is so good it deserves the recommendation.

 

[Kogure]

I'm using a XPredator X3 case. Simply not enough space inside. I already decided to hang up a radiator on the wall above the case. It'll look really good. I've been thinking about getting this one since it would look the best with my case, but I'm not sure if it will be enough. http://www.frozencpu.com/products/21112/ex-rad-640/XSPC_AX480_Quad_120mm_Radiator_w_Aluminum_Enclosure_-_White.html?tl=g30c95s570

Is 4x 120 on low speed enough to keep a CPU&GPU combo cool? I could get something like this otherwise. http://www.frozencpu.com/products/23375/ex-rad-681/Phobya_Xtreme_400_Radiator_-_60mm_Version_2_-_Full_Copper_.html?tl=g30c95s1586

 

[HEXiT]

that rad should be good enough. in real terms you would need a max of 3x120 to do the cpu/gpu and motherboard as long as the rad is reasonably dense which that 1 is. so yeah its a good choice for what you want. in fact the reviews say it will be more than you need by some margin. so will give all the cooling you need and then some. which means you can either go for low flow fans to keep things quiet or overclock to the max the system will handle.

for that case you may be able to get away with a x3 on the top and if you need it add a 120 to the loop.

 

[Drew010]

Get 3x 360mm radiotors. You probably wont even need to use fans for that setup LOL.

BAD idea, you ALWAYS need fans no matter what, unless you live in a wind tunnel

 

[Kogure]

It looks like I may be able to get a 3x120 (80mm thick) or 3x140 (60mm thick) for a much lower price since they are available in a European store. The 140 has a greater volume, but that's purely radiator volume. Would it be better, or does the extra thickness give better results?

When I calculate the volume in the exact same way for the 4x140 (40mm thick), both thick, three-fan radiators have greater volume. The 4x140 has 2400 cm², 3x120 has 3456 cm², and 3x140 has 3528 cm². All are low-FPI radiators.

 

[oczdude8]

The size ALWAYS give better performance then thickness. Always go for more a bigger rad vs a thicker rad if possible

 

[oczdude8]

Get 3x 360mm radiotors. You probably wont even need to use fans for that setup LOL.

BAD idea, you ALWAYS need fans no matter what, unless you live in a wind tunnel

That's a pretty broad generalization. You saying if I had 200 360mm rads, I still need fans?

You'd be surprised at how well radiators work when passively cooled. I have made a similar rig with a 480mm and 360mm rad (inside a 900d case) and it can run at idle at room temp with all fans off, and on full load, with only 2 fans at 600rpm to remove hot air from inside the case. I bet if these were mounted outside the case, you woundt even need fans at all.

 

[HEXiT]

The size ALWAYS give better performance then thickness. Always go for more a bigger rad vs a thicker rad if possible

thats not correct mate. fin density is what you want to look for. the over all surface area of the fins is what enables effective cooling.
the problems with high density fin is you need to use decent fans with good static pressure, then the thickness of the rad shouldnt be an issue.

 

[oczdude8]

The size ALWAYS give better performance then thickness. Always go for more a bigger rad vs a thicker rad if possible

thats not correct mate. fin density is what you want to look for. the over all surface area of the fins is what enables effective cooling.
the problems with high density fin is you need to use decent fans with good static pressure, then the thickness of the rad shouldnt be an issue.

I never mentioned fin density. I was comparing getting a thick 120 rad vs a thinner 140 rad. I am saying you gain more cooling performance by increasing the width of the rad, as opposed to its thickness.

With regards to fin density, more is not always better. high fin density can actually lower performance, if its not used with faster spinning (and therefore high static pressure fans). This corresponds to more noise.

So why would anyone want to use high density fins? because sometimes there is simply no space for multiple rads. You can only fit a single 240 rad in a case. Therefore, as you correctly mentioned, they need to maximise the cooling performance of that rad , so they use high fin density, and fast spinning (2000rpm-3000rpm fans). This is common in mini atx builds and stuff.

In this case, space is not an issue, and there is a lot of radiator surface area already. The OP mentioned he wants low fans speeds, so he MUST use low find density radiators. Its a rookie mistake to use high fin density radiator with slow fans.

 

[Kogure]

I'll look around for a 4x120/140 in European stores. My choice is very limited because I need a white one. If I won't be able to find it, I'll just get a 3x140 from Alphacool. The fans will have to run a bit faster, but I have a fan controller, so I'll be able to pick the lowest speed for desired temps.

 

[HEXiT]

swiftech do white rads and they have good reviews.