58XX cooling - what to modify next, fans or dremel out the baseplate?

[KingFatty]

OK, so my 5850 is modified by having an Arctic Cooling accelero twin turbo (non-pro version) to cool the GPU. I've also installed the stock reference cooler's baseplate to provide good contact with the VRMs.

The cooling is not capable of keeping up with my overclocks because the baseplate eventually heats up (all the VRM temps remain about the same as each other, and rise very gradually, indicating good contact with the baseplate). My question is whether to change the cooling fans for bigger ones to get more airflow across the baseplate, or perhaps use my dremel to cut slots all over the baseplate to increase heat exchange while using the current somewhat weak fans? The twin turbo blows air down onto the baseplate to cool it off using smallish 80mm fans, but when I really turn up the overclock, the baseplate gets uber-hot and the VRMs will exceed 100C.

I tested with Kombustor (i.e., furmark-like power virus), and saw the VRM/VDDC temps went over 100 degrees when I overclocked to say 920 core at 1.20V. The core was running cooler than the VRMs. So I added some stick-on heatsinks on top of the baseplate, sticking them directly onto the exposed heat-pipe soldered onto the baseplate. That helped but still the VRMs/baseplate is hotter than the GPU.

But I think the issue is that because I'm using the older non-pro version of the twin turbo that has smaller fans compared to the twin turbo pro, there just isn't enough airflow to cool off the baseplate so the baseplate gets super toasty. I mean, I saw VRM temps dropped when I added the auxiliary heatsinks, and I see that other people using the -pro version that has bigger fans apparently blows enough air across the baseplate to keep the VRMs around the same temp as the GPU. But I'm seeing my VRMs/baseplate getting about 10-20C hotter than my GPU.

I've never seen anyone modding the baseplate itself (e.g., cutting grooves into it and making it have a heatsink-like surface) to improve heat transfer, but I wonder if that's doable to get the baseplate cooler and still use the current 80mm fans? Or, is it just much easier to use a higher capacity fan (like the extra 120mm case fan I have laying around) to get more airflow across the baseplate?

 

[T_Yamamoto]

OK, so my 5850 is modified by having an Arctic Cooling accelero twin turbo (non-pro version) to cool the GPU. I've also installed the stock reference cooler's baseplate to provide good contact with the VRMs.

The cooling is not capable of keeping up with my overclocks because the baseplate eventually heats up (all the VRM temps remain about the same as each other, and rise very gradually, indicating good contact with the baseplate). My question is whether to change the cooling fans for bigger ones to get more airflow across the baseplate, or perhaps use my dremel to cut slots all over the baseplate to increase heat exchange while using the current somewhat weak fans? The twin turbo blows air down onto the baseplate to cool it off using smallish 80mm fans, but when I really turn up the overclock, the baseplate gets uber-hot and the VRMs will exceed 100C.

I tested with Kombustor (i.e., furmark-like power virus), and saw the VRM/VDDC temps went over 100 degrees when I overclocked to say 920 core at 1.20V. The core was running cooler than the VRMs. So I added some stick-on heatsinks on top of the baseplate, sticking them directly onto the exposed heat-pipe soldered onto the baseplate. That helped but still the VRMs/baseplate is hotter than the GPU.

But I think the issue is that because I'm using the older non-pro version of the twin turbo that has smaller fans compared to the twin turbo pro, there just isn't enough airflow to cool off the baseplate so the baseplate gets super toasty. I mean, I saw VRM temps dropped when I added the auxiliary heatsinks, and I see that other people using the -pro version that has bigger fans apparently blows enough air across the baseplate to keep the VRMs around the same temp as the GPU. But I'm seeing my VRMs/baseplate getting about 10-20C hotter than my GPU.

I've never seen anyone modding the baseplate itself (e.g., cutting grooves into it and making it have a heatsink-like surface) to improve heat transfer, but I wonder if that's doable to get the baseplate cooler and still use the current 80mm fans? Or, is it just much easier to use a higher capacity fan (like the extra 120mm case fan I have laying around) to get more airflow across the baseplate?

Water cooling is your next best bet

 

[KingFatty]

Water cooling is your next best bet

Any suggestions for a very cheap way to do this? I was willing to spend the $20 on the used twin turbo, because my reference cooling fan was making funny grumbling noises and had to be replaced anyway due to presumably bad bearing.

What would it cost me to get a water block that cools the GPU and also cools the VRAM and the various voltage regulators?

With my current set up, I can get a good overclock, but my overclock could be even better so long as I could better cool off the giant baseplate to keep the VRMs cooler. I wonder if my 'problem' would go away if I used a bigger fan, i.e., are the twin turbo fans just too weak (the twin turbo was not intended to be used on a 5850, it has small 80 mm fans, in contrast to the twin turbo pro that has bigger 92mm fans and is recommended for the 5850).

 

[MrTeal]

Get a dedicated heatsink for the VRMs.
http://ncix.com/products/?sku=51451&vpn=VRM-R5&manufacture=Thermalright
You probably don't need anything that extreme, but for the price it seems pretty reasonable.

 

[superjim]

So the issue isn't your core temp, it's the VRM temps you're concerned with? Why can't you just turn up the fans? Noise? 100C on VRMs really isn't bad. I've seen them at 122C on my old 6970 with hours of gaming. I'll be the first to admit I'm not 100% comfortable with that temp but VRMs are rated for ~120ish. You should see your GPU core temp stay below VRM/VDDC temps. What you're seeing is normal, the 10-20 spread between core and VRMs. The core should never be above ~95C.

Increasing fan speed to remove more heat or increasing surface area for the heat to occupy are your only options (if you don't go water). Start with the 120mm fan blowing across the baseplate and see where temps are after that. If you're still not happy with the temps, either go water cooling (with an expensive full-coverage block) or try to undervolt your GPU.

 

[KingFatty]

So the issue isn't your core temp, it's the VRM temps you're concerned with? Why can't you just turn up the fans? Noise?

The fans are set to 100%, although they are plugged into the fan connector on the video card and I'm not sure if that maxes out at a speed slower than if I connected the fans directly to 12V.

100C on VRMs really isn't bad. I've seen them at 122C on my old 6970 with hours of gaming. I'll be the first to admit I'm not 100% comfortable with that temp but VRMs are rated for ~120ish. You should see your GPU core temp stay below VRM/VDDC temps. What you're seeing is normal, the 10-20 spread between core and VRMs. The core should never be above ~95C.

That's good to hear I can run the VRMs so high in temperature, perhaps I'm worrying too much about the VRM temps I'm seeing under Kombustor/Furmark. But do the VRMs degrade the quality of the power when running at 120C? Or they maintain quality output up to 120C, then drop off afterwards?

Increasing fan speed to remove more heat or increasing surface area for the heat to occupy are your only options (if you don't go water). Start with the 120mm fan blowing across the baseplate and see where temps are after that. If you're still not happy with the temps, either go water cooling (with an expensive full-coverage block) or try to undervolt your GPU.

I'll try adding the 120mm fan toward the rear of the card pointing at the baseplate near the VRMs, to see if it changes the temperatures. I wonder if the 120mm will interfere with the cooling of the existing twin fans from the twin turbo, or improve on them, or what?

Then I'll remove the accelero twin turbo dual fans and use just the 120mm to see how that works, ziptied onto the heatsink fins where the twin turbo fans used to be. may as well do some experimentation and see how temps look; I'll also try a 2nd 120mm to replicate the dual-fan arrangement of the twin turbo, except it will be super-sized.