Not sure what radiators I need

[Virel]

I have a pair of Galax 980 to hof that I want to water cool. They have a total tdp of 500 watts. Can anyone tell me how to figure out what radiators will handle that load?

[Salticid]

Rule of thumb:  1 120 per component cooled is enough.  If you intend to OC and push your cards, add more.

 

I like to push for overkill because it can only help temps and because it gives you room for expansion if you suddenly get the urge.  So while a 28 mm 360 would be fine, I'd do a 28 mm 480 or 2 240s.  

 

you could also do a 38 mm 240 and it theoretically would be equivalent, but once you start getting thicker rads you want to make sure your fans are static pressure fans in order to have them function as well as a thinner one.  

 

https://www.ekwb.com/shop/radiators-fans

[Mick Naughty]

Are you limited by a case?

[Tristerin]

As far as I am aware there is not equation for figuring our radiator dispersion of heat.  But I can agree with @Salticid on the rule of thumb for 120mm per component is feasible.  They put Furys on 120mm rads no problem and that's up to 350w dissipation on the secondary bios.  But also, Id go big as I can for use later, additions later, etc that my case as @Mick Naughty mentions, will allow.

 

Micks also, imho, a very knowledgeable resident Loop advisor.

[Virel]

57 minutes ago, Mick Naughty said:

Are you limited by a case?

I don't think so. I have a rosewill Thor v2. It has plenty of space.

[Mick Naughty]

8 minutes ago, Virel said:

I don't think so. I have a rosewill Thor v2. It has plenty of space.

Well going by what Newegg says, large rads won’t be going in there. A mix of them could work. 2x240 and a 120 assuming they actually fit and you don’t want any rads on the actual panel. 

 

Prolly best to check build pics and and reviews to see what you can fix properly. 

[Virel]

42 minutes ago, Mick Naughty said:

Well going by what Newegg says, large rads won’t be going in there. A mix of them could work. 2x240 and a 120 assuming they actually fit and you don’t want any rads on the actual panel. 

 

Prolly best to check build pics and and reviews to see what you can fix properly. 

Okay. Thanks, so it almost sounds like maybe just as many rads as my case will accommodate then?

[Mick Naughty]

1 minute ago, Virel said:

Okay. Thanks, so it almost sounds like maybe just as many rads as my case will accommodate then?

About half really. 

[Mick Naughty]

Really depends on what fits and how far you are willing to go. More isn’t always needed but it helps. Just cost a lot more. 

[Ttnuagmada]

7 hours ago, Tristerin said:

As far as I am aware there is not equation for figuring our radiator dispersion of heat. 

The Xtremerigs rad roundup has a pretty extensive chart of measurements that can give a pretty good idea of what to expect from a rad in terms of hitting a 10C Delta T in different fan configs/pump speeds.  It's a pretty good reference for trying to figure that kind of thing out. There are some spreadsheets I've seen floating around out there too, but most of them are old and don't include a lot of newer rads.

 

 The numbers are all heat in wattage removed at 10C Delta T. 

 

https://i1.wp.com/www.xtremerigs.net/wp-content/uploads/2015/02/w10dt.png

 

As for OP; sure you can run a single 120 per card, but you aren't going to get temps that are much better than an air cooler, and you will have to run the fans so high that it will be louder than an air cooler. If you want decent fan speeds you need to be looking at 480mm of rad space at a minimum imo. A good 360 could work assuming you have good airflow and a decent ambient, but even then you're looking at 1000+ RPM fan speeds.