Looking to add 2 GTX980ti to loop, looking for some advice.

I'm planning to add a couple 980ti to my loop. Currently my CPU is the only thing being cooled, this is the kit I used (http://www.performance-pcs.com/hot-xspc-raystorm-d5-photon-ax240-watercooling-kit-19307.html). My questions are; 1) Do I need another rad and if so what size? 2) If I add a second rad, how should I run the loop for optimal cooling, or does it make a big difference? 3) Would it be worth getting a 360 rad (to replace the 240 I have now) or should I stick with the 240?

Thanks in advance.

to OCFs.

Our usual rule of thumb (I know I hate using that term lol) is for every 100w, you would need 120mm of heat surface.

Give us a spec of your complete system including the case so we know where you stand.

Case: Fractal Design Define S (Love this thing)
CPU: i7-4790k
GPU: Currently a single GTX980ti( MSI Gaming factory OC)
RAM: 16GB DDR3-1866

I suppose it's worth noting that I will most likely be overclocking the GPUs, my CPU is crap (lost the cpu lotto) and requires insane voltage therefore its only at 4.6 right now
The cooling components are those listed in the kit I linked to

A CPU in the 4.4-4.6 range is just fine. Go with the one that gives you the lowest voltage. No need to hit high numbers only if you're trying to benchmark but not needed in the real world.

As for the GPUs, make sure you check that they are compatible with the waterblocks.

For the case, I would research around and see what others have done when it came to custom water cooling in that case. What are the most rads you can fit on it and I would start from there.

The good thing here is, you picked the right kit for this because you get a premium D5 pump that can handle anything you'll throw at this loop.

Thanks for the quick replies. I can fit a 360 in the front, and the top, and a 140 on the back, I know that much, lol. Thankfully EK has made blocks for the GPU I have so I'll just need to find another gpu and I should be set in that regard. I just remembered that the pump in that kit isn't the one I got, cause they ran out of stock, I have the MCP655 (Swiftech?). I'm just real tired of my GPU heating my room (seriously, I don't need the heat on in the apartment, it damn well heats the entire place I think). Though I suppose the fact its running at 1443 mhz core (1.274v) has something to do with that I never thought to look up what other people have done with the case. I've seen people with other cases run the cpu to a rad on the back of the case, then to the gpu, then to another rad, etc. Just trying to figure out how to do that with the way I have things setup. I also forgot that I wanted to ask, how the heck do I drain my loop without making a huge mess all over my PC? I didn't think to run a drain line anywhere, lol.

danstaa said:

Thanks for the quick replies. I can fit a 360 in the front, and the top, and a 140 on the back, I know that much, lol. Thankfully EK has made blocks for the GPU I have so I'll just need to find another gpu and I should be set in that regard. I just remembered that the pump in that kit isn't the one I got, cause they ran out of stock, I have the MCP655 (Swiftech?). I'm just real tired of my GPU heating my room (seriously, I don't need the heat on in the apartment, it damn well heats the entire place I think). Though I suppose the fact its running at 1443 mhz core (1.274v) has something to do with that I never thought to look up what other people have done with the case. I've seen people with other cases run the cpu to a rad on the back of the case, then to the gpu, then to another rad, etc. Just trying to figure out how to do that with the way I have things setup. I also forgot that I wanted to ask, how the heck do I drain my loop without making a huge mess all over my PC? I didn't think to run a drain line anywhere, lol.

Click to expand...

The pump you have is fine as it is a D5. So for your better understanding, there are DDC pumps which are a smaller in design and the D5s which you already have.

You haven't given us what your ambient, CPU + GPU temps are at what settings, voltage etc. If you're worried about things heating up, why do you have such high OCs? Adding another GPU will only make things worse and adding a water cooling loop will not stop your room from heating up. Think of water cooling as a big air cooling heatsink. The radiators are the massive heatsinks. Same concept at a grander scale. Chances are, your room will get warmer and the 2nd GPU won't guarantee you those kind of clocks from the top GPU either. In general, I would lower the OCs all around if heat is an issue.

For watercooling, you will get better temps all around on hardware and give you more wiggle room to OC if someone chooses too but that doesn't necessarily mean the ambient temp will lower. It will either stay the same or increase depending on ones loop.

I think you should read up our stickies on how all of this works to get a better grasp.

I have no way to tell what the ambient is (I would *GUESS* around 20-24C initially). CPU runs around 54C with aida64. The GPU is overclocked a lot (obviously) as I play games at 2560x1440 and am a nutcase when it comes to FPS (don't ask). With SLI I wouldn't be pushing them that far if at all. I know that water cooling won't necessarily stop the room from heating up. GPU temp right now is around 80C under 100% load. I have an OK understanding of how water cooling works, but will definitely check out the stickies. Thanks again for the reply/info.

Yeah.. not going to be any cooler. You are still dissipating well over 550w worth of heat with both gpus amd cpu. Whereas now it's over 300. Think of it this way... a lighter with a yellow flame and a bonfire with yellow flames are both the same temp....which has more energy and would be tougher to cool????

You must really be a FPS snob as I run a 980ti at the same res and it pounds through everything over 60p fps really...that's a lot of coin to drop. I assume you have a 144hz monitor or something? (How about creating a signature with your hardware.. )

Yep. 144hz ASUS ROG SWIFT GSYNC monitor I've determined that with a few changes (moving res/pump combo closer to back of case, etc.) I'll be able to squeeze a 360mm rad in there. Not sure what you mean by FPS snob? I don't go around bragging about my fps, if that's what you mean.. I just like high fps. Lol. I suppose I can make up a sig.

Made sig but don't see it here..

Yes, you require high FPS, LOL! If you want to come close to it, 2 980Ti's are certainly warranted.

I see your sig.