SLI Cooling Solutions

[MoonDoggy-X]

First of all, I have to say, EVGA's ACX 2.0 cooling system is amazing. At 99% load, even for extended periods of time, my bottom card card rarely gets over 50c-ish. And thats with the core and vram overclocked as far as I could get it. My top card, however, runs about 10-15c hotter than the bottom card while gaming, and about 20c hotter during Fire Strike. I swear, the Fire Strike is like a GPU stress test! I really do use it to test my overclock stability, but I digress. Here's what my GPU setup looks like...

 

Today I removed the drive bays next to the GPUs so more air from the font intake could hit them. The temps didn't rise as fast, but they eventually rose to the low 70s for the top card. Although, I did score my highest graphics score ever . SLI isn't anything new, and I'm sure as hell not the only person running it. So, I was wondering if anyone found a solution for the SLI top card temp problem, or should I not worry because its only 70c-ish. I think even a 5-10c improvement would be awesome. How hard is it to run a custom loop for just the GPUs? I did look into those AIO GPU cooling kits for the top card, but I don't think they'd fit the cards I just ordered...

[-rascal-]

The cause for the higher temperature on the top GPU is due to the lack of spacing/separation between the two GPU's. The heat generated by the bottom GPU is rising (hot air rises) and heating up the top card.

 

Due to how your EVGA motherboard's PCI-E X16/X8 slots are arranged, you can't really do much...

 

You some-what help with the temperatures by "rigging" a fan to blow cool air in between the two GPU's. It won't look pretty though, especially since the NZXT 530 has a side window. The fan is helping force cool fresh air in between the cards.

 

[MoonDoggy-X]

The cause for the higher temperature on the top GPU is due to the lack of spacing/separation between the two GPU's. The heat generated by the bottom GPU is rising (hot air rises) and heating up the top card.

 

Due to how your EVGA motherboard's PCI-E X16/X8 slots are arranged, you can't really do much...

 

You some-what help with the temperatures by "rigging" a fan to blow cool air in between the two GPU's. It won't look pretty though, especially since the NZXT 530 has a side window.

I put a 140mm fan where the middle drive bay was at. Would getting the backplates maybe help?

[-rascal-]

I put a 140mm fan where the middle drive bay was at. Would getting the backplates maybe help?

 

The whole purpose of a backplate is to make the card more rigid -- reduce the PCB from flexing.

It can help cool the components on the back of the card, but in some situations, the backplate doesn't actually make contact with the components.

 

I probably would not get a backplate. You don't have a whole lot of space in between as it is -- adding one would just introduce MORE blockage.

 

For the fan to be the most effective, you want it very close to the GPU -- basically touching (or close to). Zip-Tie a case fan to the HDD cage.

 

 

Example, I have a 120 mm fan zip-tie'd in the top 5.25" drive bay (where you normally install DVD-RW drives, etc)

Also, you can see, with my motherboard, the PCI-E X16 slots are spaced more further apart for multi-GPU set-ups.

 

Spoiler

[Curufinwe_wins]

Honestly the best thing you could do was return those models and get blower style fans (like reference models)

The next best thing would be to get an aio kit for the upper fan and put it in the rear exhaust which would allow both to run massively cooler as less heat is placed into the case and the upper fan which is starved for air would no longer need any.

Example combine a g10 and a x41 from nzxt on the upper gpu.

[MoonDoggy-X]

The whole purpose of a backplate is to make the card more rigid -- reduce the PCB from flexing.

It can help cool the components on the back of the card, but in some situations, the backplate doesn't actually make contact with the components.

 

I probably would not get a backplate. You don't have a whole lot of space in between as it is -- adding one would just introduce MORE blockage.

 

For the fan to be the most effective, you want it very close to the GPU -- basically touching (or close to). Zip-Tie a case fan to the HDD cage.

 

 

Example, I have a 120 mm fan zip-tie'd in the top 5.25" drive bay (where you normally install DVD-RW drives, etc)

Also, you can see, with my motherboard, the PCI-E X16 slots are spaced more further apart for multi-GPU set-ups.

 

Spoiler

Its hard to tell from the pic, but a fan there is a super tight fit. Like the cables will be hitting fan blades. AND, I have 2x 980 Classified on the way, which are an inch longer than the 960s. So far, I've totally removed the 1 and 2 slotted drive bays and have just the 3 slotted bay(the one with the fan mount) sitting at the bottom. The space between the storage bay on the bottom and the optical bay at the top is just big enough for a 140mm fan. Its like I need it to float about 2 inches farther back than where you illustrated. Any suggestions on mounting something like that?

[-rascal-]

Its hard to tell from the pic, but a fan there is a super tight fit. Like the cables will be hitting fan blades. AND, I have 2x 980 Classified on the way, which are an inch longer than the 960s. So far, I've totally removed the 1 and 2 slotted drive bays and have just the 3 slotted bay(the one with the fan mount) sitting at the bottom. The space between the storage bay on the bottom and the optical bay at the top is just big enough for a 140mm fan. Its like I need it to float about 2 inches farther back than where you illustrated. Any suggestions on mounting something like that?

 

I'd wait until your two GTX 980's arrive, and see how you could tackle it with the new cards.

 

It seems like you are going to need to get creative on how to mount a separate fan there.

 

The simplest option is to get a new motherboard with a better layout...but the simplest option is not always the best option. Plus, it involves spending extra money -- to a point where I think it may be unnecessary.

[Curufinwe_wins]

I'd wait until your two GTX 980's arrive, and see how you could tackle it with the new cards.

It seems like you are going to need to get creative on how to mount a separate fan there.

The simplest option is to get a new motherboard with a better layout...but the simplest option is not always the best option. Plus, it involves spending extra money -- to a point where I think it may be unnecessary.

Or return one classy for a hybrid from evga and never have to worry about that shit. Use the hybrid in the top one. Temps will be better than any possible set of two reference or non-reference air coolers.

[MoonDoggy-X]

Fortunately my case came with a ton of zip ties!

 

 

 

 

[ConnorDahne]

I've got the same problem with my msi 970's and cramped 200r..
I'd probably do a lot better with blower style, but I've had the first one way too long..

[MoonDoggy-X]

First of all, I have to say, these Classifides are beasts!!! 1506mhz core and + 500 vram without flinching! I only stopped there because the temps were getting a little out of my comfort zone. Well, on one card, anyway. Which brings me to ongoing problem....
Even with my ghetto rigged fan, my temps on my top card are still pretty crazy. I was playing DA:I with a mild overclock and my bottom card hovered at 59-60c, while my top card was at 81-82c. Even with no overclockes, the top card stayed around 76c. So, of course, I took to obsessively scouring the internet again and came up with 3 possible solutions.

1(Most evpensive): I could try my hand at a custom water cooling loop for the GPUs only. I love my Kraken, so I'd keep it on the CPU. This solution would be around $500.00, but could potentially yield the best results. Also, It'd be my first custom loop, don't know if I should start with such expensive hardware.

2(In between): I could buy a new motherboard with the usable PCIX16 slots farther apart so my top GPU isn't so smothered. 
http://www.newegg.com/Product/Product.aspx?Item=N82E16813188160
On this board, the top two PCIX slots are x16, the middle two are x8 and the bottom one is x4. The 4790k only has 16 PCI lanes anyway, so I wouldn't lose anything using the the top slot, then on of the x8 slots. On a down side, this is an E-ATX board, and although it'd technically fit in my case, cable management will be a little snug. My current mobo goes all the way to the grommets already. See the above pics...

3(Cheapest): I could buy a new case for my rig with a big fan on the side panel that blows fresh air directly on the GPUs, like my old CM HAF. 
http://www.newegg.com/Product/Product.aspx?Item=N82E16811119225
Though the HAF is the best for air flow, my old HAF seemed like more of a cage than a case. All of those openings let a lot of sound out of the case and dust into the case. Also, the 10 fan switch in the back of my current case is kind of dope.

Which solution do you guys think is best?

[alexyy]

You could return both 980s and get a single 980ti

[MoonDoggy-X]

You could return both 980s and get a single 980ti

That'd be giving up a lot of perormance...

[alexyy]

That'd be giving up a lot of perormance...

 

 

Not really but you'll be saving on power consumption, heat and noise.