Radiating 750W of heat

CJxD · 26 Dec 2013 at 15:03

I'm looking to cool a couple of 7990s which have a TDP of 375W each in a separate loop.

My case takes two quad-120mm or two triple-140mm radiators, but I prefer the idea of triple-140mm for lower noise. I would like to use Corsair SP120 or SP140 fans.

Can anyone suggest if I can get away with a single radiator (probably using push-pull), or will I have to bite the bullet and use both radiator slots?

Jokester · 26 Dec 2013 at 15:05

Are you cooling the CPU as well? Personally I would use both slots in a single loop.

CJxD · 26 Dec 2013 at 15:33

I will do, but for the sake of taking things step by step, I'll just do the cards for now.

I heard that CPUs like to run cooler than GPUs, so it seems natural to have them in separate loops.

Jokester · 26 Dec 2013 at 15:47

Having all your cooling capacity in the same loop will help keep your water temp as cool as possible for most load scenarios.

CJxD · 26 Dec 2013 at 15:49

And it'll also heat up all the components that are usually at a lower temperature than the cooling fluid =P

Jokester · 26 Dec 2013 at 15:57

Your cooling liquid will never get that hot.

diogenese · 26 Dec 2013 at 17:53

I've just been through running two loops for CPU and CPU's, they are all in the same loop now and things are cooler and tidier! I have two 660ti's and a titan in a loop with a 3770k at 4.4Ghz all running 24x7 crunching various DC things and the hottest component is the cpu at 60c, titan is at 35c

The water temp is less than 10c above ambient.

CJxD · 26 Dec 2013 at 21:58

I'm sure my results will be different when I run these 7990s at full whack 24/7 considering all 4 cores run at 100C right now

Anyway, we're supposed to be talking about radiators!

Sin_Chase · 26 Dec 2013 at 22:19

How are you going to run separate loops with 1 radiator, clearly wont work!

Use both radiator slots on a single loop.

CJxD · 26 Dec 2013 at 22:21

-_- This is why I hate forums.

Okay, fine how do I cool 830W in a single loop, CPU included this time? What radiator(s) do I need?

Jokester · 26 Dec 2013 at 22:33

You want at least one 120mm per chip your cooling, ideally 2, so I would recommend going the whole hog and getting either 2 quads or 2 3.140mm (which are roughly equivalent to 4.120mm). I'm counting your 7990 as being 2 chips, so a total of 5 chips to cool.

Alphacool NexXxos UT60 is about as good as you can get at varying fan speeds.

Tonester0011 · 26 Dec 2013 at 22:40

CJxD said:
-_- This is why I hate forums.

Okay, fine how do I cool 830W in a single loop, CPU included this time? What radiator(s) do I need?

Well if you case can take two 120.4 rads, then fill them both up. Noise difference between 140 and 120s will be minimal as you'll be able to run your 120s at a lower rpm due to larger overall surface area (providing both rads are same thickness, FPI etc)

CJxD · 26 Dec 2013 at 23:31

Okay, cool.

Are you sure I'll definitely need 2 rads though (going back to just the dual 7990 loop) as it'd be really neat if I only use 1 (and a LOT cheaper).

Also, am I using push-pull? Any particular radiator I should get?

Tonester0011 · 26 Dec 2013 at 23:51

CJxD said:
Okay, cool.

Are you sure I'll definitely need 2 rads though (going back to just the dual 7990 loop) as it'd be really neat if I only use 1 (and a LOT cheaper).

Also, am I using push-pull? Any particular radiator I should get?

Save money on 8 fans and just push or pull not both, that covers the cost of the second rad

Having all those extra fans wont dramatically reduce temps or noise, not to the extent a second 120.4 rad will. As for rad, depends on your maximum thickness, guessing it's not a problem considering you were going to go P/P, so my i'd go with Jokester's rec of the: Alphacool NexXxoS UT60

Jokester · 27 Dec 2013 at 08:38

Push/pull is worth about 1degC over just pull which is in turn slightly better than push.

Richard2012 · 28 Dec 2013 at 08:43

hi CJxD

1st things 1st u have to give more info about your system , specially what case u using etc , saying u want this and that for 2 7990s is no help to anyone to help advice u.

all in all u are best with a single loop and like others say use 1 120mm per chip, 2 preferred but without case info etc people cant advice u whats best option.

im gonna give u a option which will give u ample cooling and basic future proofs your watercooling for the near future at least

take a look at ..

http://www.overclockers.co.uk/showproduct.php?prodid=WC-051-WC&groupid=962&catid=1523&subcat=1841 Watercool Radiator MO-RA3 9x120 PRO - black £159.95 inc VAT

http://www.overclockers.co.uk/showp...ktdetailseite&emcs2=WC-051-WC&emcs3=WC-046-WC Watercool MO-RA3 Stand - black £22.99 inc VAT

http://www.overclockers.co.uk/showp...ktdetailseite&emcs2=WC-042-WC&emcs3=WC-039-WC Watercool MO-RA3 360 Classic Cover - black £32.95 inc VAT

this is a external option that will do the job just add the fans and cables as needed to do the job then on top of that all the other equip as needed

CJxD · 28 Dec 2013 at 15:21

Thanks for all the responses. I am planning on getting a Corsair 900D for the watercooling set-up. I intended to use the smaller bays for cooling the CPU and the larger bays for the GPUs, but if you insist a single loop is better, I'll look into it.

The external radiator looks really good - I like the idea of it and it'll make it easier for me to get a simple cooling system up faster (I don't need to worry about a new case yet in that circumstance)