The 480mm vs 420 mm debate.

[SF101]

I see a-lot of recommendations for 140mm rads due to the whole no replacement for displacement argument.

But i also have been noticing even the largest cases that house 4x120mm rads can only do 3x140mm rads as the alternative, now following the rule of "no replacement for displacement" that would mean that 4x120mm is superior right?

Especially given that the Static pressure of 120mm fans is far greater also, and fan selection is better too.

So am i right to think that in the situation of say Corsair 900D or Phantek ethos primo's the 4x120mm capabilities would be the way to go rather then 140mm alternative.

The only exception i've found here is in the front intake areas where dual 140mm rads are capable and only dual 120mm rad as alternative.

But everywhere else its 4x120mm vs 3x140mm.

Just wondering if i'm correct on this outlook.

I do assume the 140mm route would make the cooling loop a-lot quieter overall however which is another consideration all together.

 

[RyanCouch]

1. math says 4x120 is better than 3x140.
2. Nf-f12's or gentle typhoons perform better than most 140mm fans
3. with 140mm fans I can't say it'd be quieter as nf-f12's at 7v are almost inaudible. so if you were to take 4 nf-f12's and do the same cooling as a 3.140 with the extra rad space you could turn down the fans overall making it quieter.

 

[S_I_N]

I have ran 3x 140mm and 2 x 140mm rads in both the Switch 810 and Enthoo primo with a decent oc on cpu of 4.6 @ 1.36 vcore (2600K) and dual 7970's with a mild oc of 1050/1500 with stock volts on them and even running a marathon gaming session of over 6 hours non stop I never felt the need to turn my fans off of low speed gpu's maintained a 43c average and cpu never broke 45c. I cannot compare to 4 x 120mm but running the 3 x 120mm and 2 x 140mm in my current case with a 4770k and the same 7970's with higher static pressure fans than my old 140's (which btw there are good 140mm statics out now) I see alot warmer temps than before and the cpu is not oc'd as of yet. 48c on gpu's and 55c on cpu But also bear in mind that the thickness of the rads changed as well. My switch and Primo were 60mm in push pull and my current case (Air 540) I'm using 45mm thick rads in push only.

 

[RnRollie]

Rad is more as just 120.4 vs 140.3 ... FPI, functionality, thickness and desired application : performance? silence? both?

For example the Alphacool UT60 is one the best allrounders & very functional (6 fittings), but the XT45 is also VERY WELL suited if you lack the space for a 60mm... And the ST30 keeps up with its bigger sisters for a very long time despite only having 30mm AIO thinkness. See martin's tests: http://martinsliquidlab.org/2012/05/01/alphacool-nexxxos-st30-360-radiator/

Of course, if one wants to jump on the slippery slope of "i want the last half degree out of it", then there are always MONSTA Rads at 80mm thickness which one can bolt a handfull of 38mm Delta's onto in Push/Pull setup

As for a bit more silence... you'ld be surprised about some of the fans ... some of the 120x38mm Delta's set at 50% perform still better with less noise as the more popular/well known/bling fans out there.

But for 120mm Rad fans, one will quickly arrive at Noiseblocker eLoop (and the Alphacool/Phobya clones) or Swiftech Helix if on a budget.

Yes, the GT-AP15 are THE fan, but the GT are out of production and soon will be out of stock everywhere also.. so think about alternatives people


In the 140mm range, the choice is even less.. Bitfenix Pro & 140mm Helix , not much else out there. But at 140mm at least you can compensate for the lack of SP by going Push/Pull with cheaper fans.

Of course, there is ALWAYS the option of taking it one step further... unless you're a lan party type or relocate a lot... one can always go for external rads like the MO-RA or the Phobya NOVA ... which offers silent performance in 9x120mm or 9x140mm or 4x180mm
(or 18x 120x38@6000 RPM Delta's in push/pull if you like the slippery slope)

 

[SF101]

following some new info ive found
4 x (120^2) = 57600 sq mm = 576 sq cm
3 x (140^2) = 58800 sq mm = 588 sq cm

3 140mm have more surface area actually.

now i guess the thickness of rads in this selection is still in play but considering the surface area is slightly higher on the 140x3 rad this changes things in the thought process here.

fans are still a big part of this equation tho.

 

[EarthDog]

Thickness, FPI, the fans on each etc are all part of this equation... Its not remotely cut and dry as it was originally made out to be.

Your best bet is to look at testing already done on your rads of choice and see what heatloads it can dissipate. Sure beats re-creating the wheel.

 

[Luke1978]

I think the OP was going on the assumption that all other things being equal which is better. Not to compare the cheapest 420 to the best 480 or vica versa... I.E. A 480 vs a 420 with all the points ED is trying to make being the same/comparable

 

[EarthDog]

If only all other things were equal...

 

[GTXJackBauer]

then there are always MONSTA Rads at 80mm thickness which one can bolt a handfull of 38mm Delta's onto in Push/Pull setup

But for 120mm Rad fans, one will quickly arrive at Noiseblocker eLoop (and the Alphacool/Phobya clones) or Swiftech Helix if on a budget.

Yes, the GT-AP15 are THE fan, but the GT are out of production and soon will be out of stock everywhere also.. so think about alternatives people

+1

there is ALWAYS the option of taking it one step further... one can always go for external rads like the MO-RA or the Phobya NOVA ... which offers silent performance in 9x120mm or 9x140mm or 4x180mm
(or 18x 120x38@6000 RPM Delta's in push/pull if you like the slippery slope)

Still sipping on papa's cough medicine I see.

I swear, you and those Delta's go hand in hand in almost every post I've read from you.

Thickness, FPI, the fans on each etc are all part of this equation...

+1

If only all other things were equal...

What is this equality you guys speak of? No such thing. Only in commie countries I hear they have that.

Anyhoooo..........

 

[RnRollie]

following some new info ive found
4 x (120^2) = 57600 sq mm = 576 sq cm
3 x (140^2) = 58800 sq mm = 588 sq cm

3 140mm have more surface area actually.

now i guess the thickness of rads in this selection is still in play but considering the surface area is slightly higher on the 140x3 rad this changes things in the thought process here.

fans are still a big part of this equation tho.

Yes at surface area of a square/rectangle, unfortunately, you have to think 3D ... add thickness AND in order to know the real surface area you have to take the width of the fins in acount... thus FPI


So, for the above equation .... at which FPI ?

Koolance offers 30 FPI rads and its very well possible that a 30FPI at 45mm thick 120.2 will offer way more more surface area compared to a 7FPI 60mm thick 140.3 ...

Simplification of the formulas allows for an easier guestimate... but its not really science

And yes, again... numerous other factors come into play...
not only FPI, but the material... copper fins are better than alu fins, etc
see also http://www.overclockers.com/forums/showthread.php?t=622959

As for the Absolute Surface Area formula... Martin or Skinnee or Stren worked it out... i cant recall the exact formula... Its a variation of the HEATSINK Surface Area calculation... you take it apart and spread out all those fins till you get a few square feet




PS @Jack... at 30 FPI.. the use of Delta's might be required

 

[JTRisdon]

The surface areas of the fans and Rads are fairly close between 420 and 480, yes 480 is 6cm longer but it’s also 2cm narrower. I think this is more of a compatibility thing. There is presumably a negligible difference between the two other than if it will fit into a midi tower case.

 

[bmwbaxter]

Holy necromancy friend. This post is from 2014.

 

[Zerileous]

Whenever I see these part of me is glad that people are digging into the wealth of knowledge compared herein.

 

[trents]

I see a-lot of recommendations for 140mm rads due to the whole no replacement for displacement argument.

But i also have been noticing even the largest cases that house 4x120mm rads can only do 3x140mm rads as the alternative, now following the rule of "no replacement for displacement" that would mean that 4x120mm is superior right?

Especially given that the Static pressure of 120mm fans is far greater also, and fan selection is better too.

So am i right to think that in the situation of say Corsair 900D or Phantek ethos primo's the 4x120mm capabilities would be the way to go rather then 140mm alternative.

The only exception i've found here is in the front intake areas where dual 140mm rads are capable and only dual 120mm rad as alternative.

But everywhere else its 4x120mm vs 3x140mm.

Just wondering if i'm correct on this outlook.

I do assume the 140mm route would make the cooling loop a-lot quieter overall however which is another consideration all together.

What? It depends entirely on the fan. With the same fan and blade design, same RPM the static pressure should be the same, shouldn't it?

 

[Woomack]

I guess he meant that is easier to find good, high air pressure fans in a 120mm size than 140mm. On the other hand, this thread has 6 years and there are more good options on the market nowadays.

One more alternative which works surprisingly well - NF-A12x25 fans with NA-SFMA1 mounting frames. I guess this option won't be popular but fans are great and provide about the best results. In my tests were as good or better than 140mm fans. Tests with Alphacool 280 rads.