H115i + be quiet Dark Base Pro 900
 

I'm getting pretty bad results with cooling on this case and h115i. Idle sitting somewhere between 35-40, and I think that's a bit high. Fans start and stop like mad, even on the quiet profile. And god they're LOUD.

The case has 3 x 140mm fans, very silent. Currently mounted - two front (intake), one on the back (exhaust). The H115i is set on the top of the case as exhaust, radiator outside the case metal skeleton in the plastic enclosure and fans inside the metal case.

The dark base pro has side vents and I'm pretty sure this is the issue. So the whole top is solid apart from a few lines in the back and then the lateral areas have airways (see pictures).

Any clue how I can set this up better? Should I reverse the fans and the radiator?

http://imgur.com/a/l8L2d

Can you get a "high airflow" top?
 

I to suspect it's the lack of holes and wonder can you get a "high airflow" top that has more holes in it?

What I would do is cut holes over the radiator and fit a covers such as http://www.ebay.co.uk/itm/272424584621

I suspect reversing airflows would not really help

attach the CL4 [home] tab
 

I suspect you should change the group to H115i Temp.

I also advise you to attach the CL4 [home] tab and fan config panel so we can see all the information without http://imgur.com/ the adverts.

I've inversed the position of the radiator and fans (radiator inside, fans outside) and I'm getting better results, base temperatures are somewhere around 28-33C and in high loads 40-45C.

Also setup a custom profile for the H115i Fans, as they were still loud in the Quiet preset.

Would it be worth it to modify the case with these kind of temperatures?

Same here
 

I have same setup and case with same results. I am using a Z270 MSI Gaming 5 mobo. It has a pump header on the mobo. Can I attach the fan/pump header forum the H100i V2 to the pump header? Alsu you say you made the fans intake instead of out flow? I may try that. Any other info or advice you may have appreciated before I do this. Think I will also change Corsair's thermal paste with some Artic Silver. Thanks

Unfortunately, it is likely the case design is always going to create higher than expected coolant temperatures. I don't think we have seen anyone with a DB900 complain, but there have been several Silent Base 800 owners with the same issue. That case has a theoretically better "dome top" that has a bit more air space. Ultimately, it is the same problem of the waste heat being trapped around the radiator until pushed out. I am not sure anyone has tried modding any of these cases yet.

This was the most recent one I can remember. Is it possible to front mount the H115i in that case?

Radiator mounting
 

I think the radiator should be mounted top on inside of case. If you have it on top there will be no clearance between top cover and fan not allowing any air flow.

Dark Base Pro 900
 

I may try running it as is with the top removed and see how the temps do. If we see a 5-10 degree drop we found our culprit. My case is hard to get to as I have a disabled arm. If anyone out there can get to it first please let me know the results. Thanks.

It's still set as exhaust, but now the radiator is inside the case and the fans outside (in the top area) - see attachment. It works better for me in this setup.

It is, but it would leave you with a single drive bay, you'd have to dismount all the others to make room.

Front mount
 

Yes that's how I have mine but Im still getting readings near 40 in BIOS. Very hard to get exact temps as MSI software temps fluctuate all over. Guess the true test is to check temp in bios. Right now my room is 72F and my temp is 40C at idle. Still too high. My old Antec 900 with a Corsair Hyper 212 with a i7-3770K would go down to 29-30C at idle. Also in regards to front mount you are correct. It only leaves room for 1 drive bay. Fortunately that's all I need as I have 2 M.2 drives installed but not sure I want to disassemble everything, Would you mind doing the test at idle with the top cover removed being you are working on your PC now and let me now if there is a significant temperature drop? Thanks a lot.

At some point, you both might want to try turning the fans to intake. Normally, I would not choose this option as the 'external cooler air' isn't worth much. However, it is probable the limitation is the getting the waste heat out of the area versus actual airflow across the fins. This puts the waste heat in the case, but with some strong rear exhaust you might be able to offset that penalty.

Whether the fans are above or below the radiator shouldn't matter from a resistance standpoint, however the tone is often different. This is something you can decide on your own. More often unique case features or materials make one or the other more appealing.

The other thing to keep in mind is this not a fatal obstacle. You can go on as your are without compromising your normal use. The real nuisance is the loud fans. That can be addressed by shifting the entire water curve up from its designed 20-40C range to something that reflects your baseline coolant temperature, perhaps 30-50C or whatever. Also, in any case full Be Quiet fans, the grey SP140L's will always be the loudest thing going. You may want to consider replacing them with a fan designed for a lower noise profile. You don't want or need to run speeds above 1500 rpm for the total power draw you can get from these CPUs and can keep the any fan below that.

Focus on the difference between room temperature and the coolant temperature (H100i v2 Temp/H115i Temp) at idle or load. There are a number of reasons for higher than expected CPU temps and who knows what state the CPU is kept in while in the BIOS. If the problem is environmental as expected, you will see a noticeable difference between the room temperature and the coolant temperature at idle. A normal difference might be 4-7C. I suspect you are on the higher end of that. At idle, it may be able to stay close to expectations, but at load is where the problem may worsen. When it actually has some more substantial heat to dissipate, it the coolant temps may again go higher than expected.

Case top off, everything else mounted

@idle
30~32C Package temp
24~30C Core Temp

in load temps go to around 40-45C

I'd say temperatures are a bit more stable, they don't vary as much, but honestly there's not much of a difference, even though I thought it would be.

Any suggestions of a test I can run to observe peak temps and how the cooler responds. Never that big into over clocking but know there are programs (Prime95) that test these things. Just need a short one to test CPU temp. Would 5 minutes at Intel Extreme software do the trick.? Thanks.

Thanks for doing that for me. That's pretty significant I think. It went down about 10 degrees for you if I am correct?. If that is the case I may convert mine to front intake and see what I get. It will take me a couple of hours but if I do I will get back to you with my results. I guess with your build thats not an option but as I have only one 4TB HDD and 2 M.2 drives I can do it. Thanks.