problems with heat in my 800D

[krsboss]

Hi, I have read several other threads in this forum dealing with how to best use your 800D with air cooling, however there's nothing really that relates specifically to my machine.

 

The problems really only started when I installed a 2nd GTX-470 in SLI wiith my existing 470...I know these cards can put off a lot of heat however this wasn't a problem with only one! Also, due to everything I have in the case, I had to install them right next to each other :eek:

 

Currently I have my H70 (replaced the stock fans with Coolermaster 90 CFM LED fans) on the top panel set as an exhaust with 2 more Coolermaster 90 CFM LED fans as exhaust fans along the top.

 

I have replaced the bottom 14cm stock fan with a Noctua NPF-14 and the back case fan as an intake using a Lan-Li 14cm LED fan (gotta have pretty colors with a clear side panel right?!)!

 

I've tried other configurations of the fans and moving things around, however this is the best configuration to date...

 

so anyway, the problem is really with the bottom card which is also the master. It's running ~30 degrees hotter than the top (slave) and unless I manually set the fan speed to 100% it will get to ~90 centigrade reasonably quickly during graphic intensive programs, however running the fan at 100% gets pretty noisy and is not really an option!

 

I know the problem must be cooling related, firstly from the NVidia SLi forums & secondly if I switch the GTX-470s over then the card which was originally the slave (now the master) gets to similar temperatures as the other.

 

In order to combat the noise I have taken to sticking a freezer pack :eek: standing upright next to the GPUs which allows me to run the fan at 80% without getting the master-card too hot..however that's still pretty noisy and clearly not a long-term solution!

 

I would greatly appreciate some input if anyone can help...I'm seriously considering selling my whole PC and getting an EVGA watercooled GTX-580 :p:

 

(atm my next step is to get a 5.25" intake fan assembly for the front and switching the rear fan to output!)

[shuffle]

Have you tried just using the H70 with the fan either side as exhaust, and doing away with any other fan in the case? Also run the 2 H70 fans at 600-800rpm, ie minimum.

I found using less fans a solution, as they cancel out the graphics cards job of keeping cool

sorry ive never used a 2 card set up, but worth a try

[krsboss]

Currently the H70 is acting as an exhaust, however there weren't any problems keeping 1 GTX-470 cool...the problem is now that I have 2...gonna try moving some things around inside the case see if I can get them with a PCI-E slot between them (for my wireless network card)...problem is, the video cards are so big it interferes with cabling on the motherboard and the lowest cable holes in the 800D...so a lot of rewiring!

 

...other than this looks like I'm gonna have to get me some water cooling on the go, which is a real shame as I just got the H70!

[Johannespaul]

I have also had problems with heat with my 800D case. The first problem lays with the insufficient air supply available to the intake fan. As you know, the intake fan has to pull air from the outside through a 1 inch gap to bottom of the case and through a filter while fighting the PSU for air. For what air gets through, the GPUs gobble a huge amount of that up. The second problem is the direction of the air flow. In a multi GPU set up, only the bottom GPU sees most of the cooling benefits. The GPUs above it have to "grab" air from the perpendicular moving air. Whatever is left over blows out the top with very little, if any, reaching the meat of the motherboard. Remove the two top front fans and put your hand over the front rad grill. You will feel the air flowing straight out. This is why the case benefits from flipping the exhaust fan. I have tried every fan configuration this is what I found:

 

1) Add three 12 cm fans to the top: No difference in temps and a lot of noise.

 

2.) Flip the exhaust fan: Largest difference in temps but GPU was not affected. Lots of dust let in the system.

 

3.) A combo of 1 and 2. Lot of noise and dust with very little gain over 2.

 

I figured that the only thing I could possibly do was to mod the case with a side fan. I picked the Silverstone 18 cm fan with its matching filter blowing over my video card and chipset heatsink. Their was a mass drop in all temps and GPU fan speed. This case now matches my old TT Armor 23cm in NB, SB, and MB temps (my CPU is on an H50 and stock clocked so I don't worry about it too much) and exceeds it in GPU cooling. My TT Armor had 2 12 cm intakes, a 23 cm side fan, and an H50 on exhaust. My modded 800D has a 14 cm exhaust and the H50 on exhaust over the CPU of the MB along with the rest of the regular cooling. I added a link to a forum post I did on it below that contains pics and results.

 

http://forum.corsair.com/v3/showthread.php?t=90922

[krsboss]

:S well keeping the card cool wasn't a problem with one GTX-470, just adding a 2nd is really causing some issues.

 

I've seen a few mods whereby people have put a side-fan in their 800D window, but I really don't want to have to resort to that...I'd probably rather dish out some deniros and go with water cooling for the twin cards instead....

 

...still, I've moved the 2nd (and hotter) 470 down one slot, (re-arranging a lot of other things in my case along the way) and it's resulted in a 4 celcius drop in a max GPU temp on a Furmark benchmark however it's still getting too hot on gaming sessions unless I manually set the fan to 80%+, put a freezer block inside the case or both!

 

I've also tried a varied of makeshift ducts to direct airflow towards the GPUs, however none have had an affect on the Furmark benchmark I've been using to check overall temps!

[slotrod]

You mentioned having to lose the use of the H70 if you go water cool WHY if it's not broken don't fix it. If you want to water cool just do the Vid cards and maybe the board. With two 470's you would need a double loop or you will heat up the processor. Put a 240 on the bottom and you will be good to go.

[krsboss]

Interesting! So....with such hot video cards the coolant coming in from the processor would be too hot anyway?

 

If I were to get some water cooling on the go for the 470s I guess the thing to do would be to have the coolant going into the hotter card first, then the cooler card second, or would I need a double loop regardless?!

 

It's still a major investment to get water cooling on the go, plus I've never played around with video cards so much as to remove casing and install a water-block o.O

[FlawlessSoul]

For two graphics cards you'd want a single loop for your GPUs (both in one) and another loop for your CPU+chipset (if you're watercooling it).

[Yellowbeard]

Also, keep in mind that the stock fan speeds for the GPUs are VERY low to reduce noise. I see you set 80% for gaming which is loud but sometimes necessary. I have had the same problem and even with cards out on a test bench.

[slotrod]

Yes I would suggest what Yellowbeard said first crank up the vid card fans first and see what you get. If you single loop the vid cards cool the colder card first so you do not heat it up from the hotter one.

[krsboss]

really? I would have thought to cool the hotter one first as it needs the cooling more...but I guess the opposite also follows the same logic!

[alphasig298]

I have a similar issue with my 800D running 3 GTX 465's. What I had to do was take the cards apart and reapply thermal paste. I used the new MX-4. Moreover, I replaced all my fans with higher CFM and used my H70 as a intake. Finally, I use EVGA's precision tool so I can adjust my GPU fans based off of the temps of my cards. Thus, I start my cards out at 50% and scale it up to 100% at 85 deg Celsius. By doing that it keeps the temperatures around 75 deg celsius on my hottest during full load. I found that by upping the fans higher on the GPU at lower temperatures actually keeps my cards cooler.