How much rads for CPU + GPU?

[Moses Sandals]

Hi everyone,

I'm looking to transition to watercooling my i7 4770k and 780ti. However, I'm unsure how much rads I should get to sufficiently cool the parts. I was thinking about getting a 360mm & a 120mm in my Phanteks Enthoo Pro Case although, my friend said that would be overkill...... :wacko:

Any suggestions would be greatly appreciated!!! 

-Sam

[Lolzious]

A 240 rad is enough, but come on, you're water cooling, not buying a 212 Evo

Go for as many as you can!

[thekeemo]

I would go for 2 x 240mm which is the same as 1x260 + 120 

dont forget to get thick rads

[Tai Tran]

If you're overclocking, at least 120 for CPU and 240 for GPU. I would personally go for 2x240. If I a have a big ass case however, I would go further.

[Agosto]

I'd say a ST30 360mm on top and an XT45 240mm or 140mm on the front/bottom ( depending on your HDD needs )

[skline00]

I like the way Agost thinks!  

[froobs]

i have a 750d, i plan to get an ekwb kit, no idea how thick the rad should be for clearance at top, is 360mm good for both or should i do one 360, 240 at bottom intake, or 280 front intake?

[CalebTheEternal]

Hi everyone,

I'm looking to transition to watercooling my i7 4770k and 780ti. However, I'm unsure how much rads I should get to sufficiently cool the parts. I was thinking about getting a 360mm & a 120mm in my Phanteks Enthoo Pro Case although, my friend said that would be overkill...... :wacko:

Any suggestions would be greatly appreciated!!! 

-Sam

Well if you can get 2 360

 

I might do 2 360 just for my CPU cuz yolo right?

[blu4]

A rule of thumb is 120mm RAD per processing core. So if you had a CPU and two cards in SLI you would need to get a 240mm and a 120mm radiator. This table summarizes radiator sizes and wattage dissipation-

:

source: http://www.tomshardware.co.uk/forum/277130-29-read-first-watercooling-sticky

[LeighPing]

Something to consider, two or more big rads will allow you to turn the fans off for times when silence is required. I use 2 x 360 rads and rarely need to switch the fans on, unless gaming or benchmarking. It keeps things quiet and relatively dust free.

[DjMojoe]

I use 2x 240 wich is enough for a slightly OC 980 + 4790k but i would go with bigger/ more rads if i could. ( there is no space left in my Evolv Case )

If you have the money and the space get crazy on rads. 

With your case i would do a 360 in the top and a 240 in the front. 

[asquirrel]

Hi everyone,

I'm looking to transition to watercooling my i7 4770k and 780ti. However, I'm unsure how much rads I should get to sufficiently cool the parts. I was thinking about getting a 360mm & a 120mm in my Phanteks Enthoo Pro Case although, my friend said that would be overkill...... :wacko:

Any suggestions would be greatly appreciated!!! 

-Sam

 

 

source: http://www.tomshardware.co.uk/forum/277130-29-read-first-watercooling-stick

 

Ok, here's how to use that fancy chart above, because I want to give you a good 'average' number, we'll use the average of .00023 watts per mm3 for our radiator performance. So what do you need to know in order to know how much radiator you need? Simple: Thermal Design Power + math.

 

i7 4770K TDP (stock): 84W

GTX 780 Ti TDP (stock): 250W

 

84 + 250 = 334W of heat to get rid of.

 

334 / .00023 = 1,452,173.91 mm3 {So this is the amount of radiator volume you need in order to get rid of 334W of heat with a 10C delta @ 2000 RPM on the fans}

 

Some options:

--120mm fans with a 30mm rad thickness--

1,452,173.91 mm3 / (120 * 30) = 403mm

So this would be a 480mm rad, ie 4x 120mm, or two 2x120mm radiators in serial/parallel.

 

--140mm fans with a 30mm rad thickness--

1,452,173.91 mm3 / (140 * 30) = 345mm {so here a 480mm (3x140mm) radiator would work}

 

--120mm fans with a 60mm rad thickness--

1,452,173.91 mm3 / (120 * 60) = 201mm {so a 240mm radiator would be sufficient here}

 

Closing thoughts:

1. You may have clearance issues with a 60mm thick rad. Also, you'll need to invest in strong fans (gentle typhoons, noctua NF-F12s, etc) in order to maintain good airflow through a 60mm thick radiator without needing push-pull
2. If you decide to slow down your fans from the 2000 RPM rate for added silence, you may need push-pull to make up for the now-lower static pressure (fan RPM directly correlates to static pressure; slower fan = less static pressure)
3. That chart is based on 2000 RPM fans. Linus prefers ~1200 RPM for silent running. Radiators scale linear-ish with fan RPM so if you decide you want silent, double your radiator amount.
4. Those numbers above are to reach a 10C delta with the room temperature. This is *very* aggressive. Less radiator with the same 2K RPM fan speed will yeild a higher delta over the room. Lowering both the fan speed and radiator surface area will quickly raise the delta.
5. If you plan to overclock either the card or the CPU, be sure to recompute all the numbers given the new overclocked TDPs. The formula for that is:

(stock TDP)*(clock/stock clock)*((voltage/stock voltage)^2)

 

An example for the i7 4770K overclocked to 4.8ghZ @ 1.35v would be: 

84 * (4800 / 3500) * ((1.35 / 1.25)^2) -->

84 * (1.37143) * ((1.08)^2) -->

84 * (1.37143) * 1.1664 == 134.37W

 

As you can see in the above formula, keeping the voltage as low as possible for a stable overclock is the key to getting a low TDP when overclocking! Cheers.

[fireincairo]

Edit: Sorry for the thread necro.  I intended to post this on another thread.   :blink:

 

 

Ok, here's how to use that fancy chart above, because I want to give you a good 'average' number, we'll use the average of .00023 watts per mm3 for our radiator performance. So what do you need to know in order to know how much radiator you need? Simple: Thermal Design Power + math.

 

......

 

(stock TDP)*(clock/stock clock)*((voltage/stock voltage)^2)

 

...

 

As you can see in the above formula, keeping the voltage as low as possible for a stable overclock is the key to getting a low TDP when overclocking! Cheers.

 

 

If you have the time, I would appreciate any input on my SLI titan X that I am in the process of converting to liquid cooling.  I've purchased EK GPU waterblocks and the Fractal Design R5 for the build, which can accommodate a 420mm radiator on top and 360mm on the front.  

 

My system on air cooling:

-i5-3570k @ 4.2ghz from 3.4ghz

-SLI Titan X (EVGA Superclocked) x2 with manual overclock to 1217 Mhz (1306 Mhz boost) & 1953 MHz memory

-750w Corsair PSU 80 gold

-Gigabyte ga-z77-ud3h

 

I'm assuming i'll need to upgrade to a larger PSU ie 1000W to power everything sufficiently

-A 4.5 Ghz OC will require ~119W

-Titan X max TDP is 250W, but will be higher with overclocking.  

 

Assuming I could achieve 1.452 Ghz, according to the formula:

(250)*(1452/1202)*((1.218/1.162)^2)

(250)(1.20799)*(1.04820)^2)

(250)*(1.20799)*(1.0987)=331.81W per card (however, from what I've read, TDP can't exceed 275W due to its power limits)

119+331.81*2 = 782.61W or 119+275*2 = 669W

 

669W - 782.61W as TDP is quite significant!  I'm completely new to water cooling, although after about 10-15 hours of research at this point I have learned a lot; I'm concerned I may not correctly plan for enough heat dispersal and have to rebuild the water loop.  Initially I planned to only use one high quality 360mm radiator (based off the chart above that states dissipation of 1000w for 10C delta), but now that seems insufficient for a quieter setup.  

 

I could purchase two of the koolance CU1020v (or one and a 420mm xspc ex420, although I haven't seen performance tests with it), but is that enough to cool two overclocked GPUs and CPU?  I'd like to keep it as quiet as possible, particularly considering the fractal case was made to absorb noise and I'll have this baby beside my TV in the living room.   :lol:  

 

Thanks for the input

[gamerking]

i do 100-250w per 120mm rad place since i want a quiet pc not a jet next to me . normal gpu+cpu you want 4 120mm for that ,abit more if your overclocking heavily . for 970 you can get away with 1 less but you got a 780 so 4-5 120mm for a quiet pc  . but if noise ant a issue then some nice static pressure fans and good air  flow and 4 120mm is fine then

[GirlFromYonder]

On 24/03/2015 at 7:18 PM, asquirrel said:

 

 

 

Ok, here's how to use that fancy chart above, because I want to give you a good 'average' number, we'll use the average of .00023 watts per mm3 for our radiator performance. So what do you need to know in order to know how much radiator you need? Simple: Thermal Design Power + math.

 

i7 4770K TDP (stock): 84W

GTX 780 Ti TDP (stock): 250W

 

84 + 250 = 334W of heat to get rid of.

 

334 / .00023 = 1,452,173.91 mm3 {So this is the amount of radiator volume you need in order to get rid of 334W of heat with a 10C delta @ 2000 RPM on the fans}

 

Some options:

--120mm fans with a 30mm rad thickness--

1,452,173.91 mm3 / (120 * 30) = 403mm

So this would be a 480mm rad, ie 4x 120mm, or two 2x120mm radiators in serial/parallel.

 

--140mm fans with a 30mm rad thickness--

1,452,173.91 mm3 / (140 * 30) = 345mm {so here a 480mm (3x140mm) radiator would work}

 

--120mm fans with a 60mm rad thickness--

1,452,173.91 mm3 / (120 * 60) = 201mm {so a 240mm radiator would be sufficient here}

 

Closing thoughts:

1. You may have clearance issues with a 60mm thick rad. Also, you'll need to invest in strong fans (gentle typhoons, noctua NF-F12s, etc) in order to maintain good airflow through a 60mm thick radiator without needing push-pull
2. If you decide to slow down your fans from the 2000 RPM rate for added silence, you may need push-pull to make up for the now-lower static pressure (fan RPM directly correlates to static pressure; slower fan = less static pressure)
3. That chart is based on 2000 RPM fans. Linus prefers ~1200 RPM for silent running. Radiators scale linear-ish with fan RPM so if you decide you want silent, double your radiator amount.
4. Those numbers above are to reach a 10C delta with the room temperature. This is *very* aggressive. Less radiator with the same 2K RPM fan speed will yeild a higher delta over the room. Lowering both the fan speed and radiator surface area will quickly raise the delta.
5. If you plan to overclock either the card or the CPU, be sure to recompute all the numbers given the new overclocked TDPs. The formula for that is:

(stock TDP)*(clock/stock clock)*((voltage/stock voltage)^2)

 

An example for the i7 4770K overclocked to 4.8ghZ @ 1.35v would be: 

84 * (4800 / 3500) * ((1.35 / 1.25)^2) -->

84 * (1.37143) * ((1.08)^2) -->

84 * (1.37143) * 1.1664 == 134.37W

 

As you can see in the above formula, keeping the voltage as low as possible for a stable overclock is the key to getting a low TDP when overclocking! Cheers.

THANK MANS, HELP A BUNCH