[SOLVED] Noctua LNA adapter and RPMs reported

[GregP74]

I was thinking about using this low noise adapter that came with my NH-D15S's NF-A15 fan. Obviously it slows the fan down, but does the BIOS still report the correct RPMs? If I add a second fan to that cooler would I be better off running one off the CPU_OPT header rather than using a splitter if I've thrown the LNA into the mix? (Especially because it sounds like the fan that comes with the kit is a 1500 rpm and the retail ones are 1200?)

 

[Darkbreeze]

Don't use the LNA adapter. It defeats the entire purpose of the cooler which is to offer top shelf cooling potential. If you add a second fan that is 1500rpm you want to add it towards the back from any fan currently installed so that it does two things.

One, does not create a logjam for airflow from the front fan, in other words, create a restriction for air already trying to get through the heatsink.

Two, HELP the front fan, but reducing the static resistance to airflow through the heatsink and also eliminate any dead spots or reversion leaks.

With a two fan setup you always want them either equal OR the higher RPM and CFM model to the back. Putting a higher performance fan in front does no good since you'll be trying to push through a heatsink AND another fan, and that is senseless.

If you want to reduce noise levels, I'm not sure what to tell you. You're already using one of the quietest fans on the market, so really the only other thing you can do is modify the fan curve in the BIOS if your BIOS allows you to create custom fan curves, or choose the silent preset if currently using the performance or standard one, or get a different motherboard that DOES allow you to create custom fan curves.

As far as the headers go, I'd just use the splitter and run both fans off the CPU-FAN header. That way you know they are both reacting to the same criteria, all the time. If you use the CPU_OPT header for the second fan, which is fine too, I'd still avoid using the LNA adapter at all. If you use that, you might just as well have bought a smaller, less capable cooler.

 

[GregP74]

Thanks! I'm not too worried about the noise. I rarely hear the fans come on anyway. Only reason I was really interested in the LNA was not causing problems with the different fan speeds, but that makes sense to have the lower speed one pushing into the faster one.

With my current setup a half hour of AIDA64 only gets temps up to 81 or 82 with regular jumps up to 88 then it comes right back down within seconds. I'm not sure adding another fan for $20+ is really worth bringing it down a couple degrees.

 

[Darkbreeze]

Hold up.

81-82°C, with WHAT hardware, and running WHAT? What are you running when you see those temps?

What is your CPU, motherboard, case and case cooling configuration?

 

[GregP74]

https://pcpartpicker.com/b/Rsk6Mp

Those numbers come from leaving the aida64 stress test thing running for a 1/2 hour or so.

 

[Darkbreeze]

Aida shouldn't stress your CPU to anywhere near TDP, so if you are exceeding the recommended temp running Aida, you'll definitely be exceeding the recommended temp running Prime95 Small FFT unless you are running AVX while testing.

Download Prime95. Install it. Run it. Choose the "Small FFT" option. Not "Smallest FFT". Just "Small FFT". Uncheck/disable the option for "AVX2" and then "AVX" in the options down below on the main window. Then run it for 15 minutes. You can also use the OCCT small data set, same thing, disable AVX and AVX2. If at any point you exceed 80°C, stop the test by clicking "File---->Stop" and then exit the program. Don't use the X in the corner like you would for most programs or it will just minimize and keep running in the system tray.

Where are EACH of your case fans installed, and EXACTLY which direction, in or out (Intake or exhaust) is EVERY single one of them blowing? Which way is the fan on your heatsink oriented?

Something definitely isn't right because there's no way you should be exceeding 80°C with that heatsink running Aida.

 

[GregP74]

I'll download that and give it a try.

Current setup is a Gigabyte X570 Aorus Master board with a Ryzen 3900x. Meshify S2 case. Chassis fans are all Noctua NH-14a pwm -- 2 front intake fans one slightly below the very top and one a little above the psu shroud on the bottom. Exhaust fan is in the rear. Single fan on the nh-d15s is a NH-15a blowing towards the back.

Fans are set to quiet in bios and are all running when it's on.

 

[GregP74]

Ok, I gave Prime95 a run with those settings. After 15 or 16 minutes it maxed out at 76.8.

Something I did notice is that the back of the case is only about an inch and a half rom the wall. That could be hindering the exhaust. Gonna be kind of difficult to move it outwards much more so I'm wondering if adding another exhaust fan blowing upwards back there (or moving that one) would be a good idea.

EDIT: Ran it again for another 15 and this time it only got up to 70.1

EDIT 2: Those numbers are from HWInfo64

 

[Darkbreeze]

Yes, those temps are pretty good. Much better actually.

Yes, adding another exhaust, in the TOP-rear location, would be extremely helpful. Especially since that is where about 60% of the heat in the case is generated and accumulates, from the heatsink and the VRMs on the motherboard, all of which are in that top back corner.

A single exhaust fan is never enough IMO unless it's a very light duty machine.

Probably don't even need to add another fan to the heatsink, although it wouldn't hurt, because adding that top rear exhaust fan might actually drop you another couple of degrees overall, but doing both I think would put you in a very favorable configuration.

 

[GregP74]

Yes, those temps are pretty good. Much better actually.

Yes, adding another exhaust, in the TOP-rear location, would be extremely helpful. Especially since that is where about 60% of the heat in the case is generated and accumulates, from the heatsink and the VRMs on the motherboard, all of which are in that top back corner.

A single exhaust fan is never enough IMO unless it's a very light duty machine.

Probably don't even need to add another fan to the heatsink, although it wouldn't hurt, because adding that top rear exhaust fan might actually drop you another couple of degrees overall, but doing both I think would put you in a very favorable configuration.

Yeah I don't push this thing that hard I think the one on the cpu cooler is probably enough. I had been thinking about that top exhaust as well as a 3rd intake in front. Can't see it real well in this pic but a plate at the front of the shroud and about 3/4" of the fan is below that level. Seems like most of it would be blowing at cables and the power supply and not be very helpful. At the same time I want maintain positive pressure if I had a second exhaust so maybe even if another intake doesn't cool a whole lot it'll at least do that.

 

[Darkbreeze]

Positive pressure is for dust suppression. Negative pressure benefits cooling performance.

I prefer to see a balance, so a "neutral" pressure configuration is what I generally prefer to loosely aim for. In truth, there are so many holes and gaps in most cases that an extra fan one way or the other probably doesn't bring all that much to the table in terms of pressure anyhow unless you seal them up. Your case has good front filtration so dust shouldn't be a HUGE problem anyhow. Not a lot of point in forcing air down under the PSU shroud, but it won't hurt either.

Adding both, another front intake and a top exhaust, is absolutely acceptable and is actually exactly how I have my Define S configured. Obviously, that doesn't have a PSU shroud though. Even the same NF-A14 PWM fans, although they are the Chromax version which come black, for 5 of them, while the rear exhaust is the NF-A14 PWM iPPC 2000rpm industrial version, and the top rear exhaust is a standard NF-A14PWM that I colored black using vinyl dye before I bought the other fans.

 

[GregP74]

I remember building a system some years back with a Define S case and trying about 100000 different fan configurations. I spent a month trying to decide between an AIO and air cooling. I think I finally ended up with the three in front one in the back and one on top, not because it was drastically better but because it didn't over heat and I was tired of working on it and could ignore it. And then a few months later they introduced the Define C and I switched to that and started the whole process over 😀

 

[Darkbreeze]

Well, at least you've stuck to Fractal design. I think they are one of the top three case manufacturers along with Phanteks and Corsair. Lian Li is good too, but all their really decent cases are exorbitantly expensive. The 011 dynamic is decent, but I don't particularly like the configuration the way it sits now. I haven't figured out how to make it better, but I will.

I'm actually working on my own case design, so if that works out, I might just ditch all these guys. LOL.

 

[GregP74]

Well, at least you've stuck to Fractal design. I think they are one of the top three case manufacturers along with Phanteks and Corsair. Lian Li is good too, but all their really decent cases are exorbitantly expensive. The 011 dynamic is decent, but I don't particularly like the configuration the way it sits now. I haven't figured out how to make it better, but I will.

I'm actually working on my own case design, so if that works out, I might just ditch all these guys. LOL.

I am a big fan of Fractal Design too. When I had to do this build I was going to keep everything in my Define C, but I guess buying a bunch of hardware made me want a nice new case to put it all in. I ended up with an NZXT h500 and wasn't happy. It was short and hard to get to plug in the 12v atx cables and the exhaust fan, and getting that big Noctua cooler in gave me fits. It made me mad the night I started and the next morning I decided it had to go and I was going to order a Meshify C. They weren't available ANYWHERE at the time so I ended up going with the big one. It's honestly way more than I need but it's easy to work with and I'm happy. I really wish FD would introduce a Meshify "M" medium sized one kind of half way between the C and S2.

 

[Karadjgne]

Umm ram? Should be in A2/B2. From the picture it looks to be in A1/B1, which with Ryzens almost always runs ram at funky speeds.

Aida runs AVX and linpack bursts, so you'll get loads of @ 80% to 100%, but with the instruction sets it'll give an artificial load approaching @ 130%. That's a totally fake number, anything you do can only tax the cpu to 100%. So it gives some really screwey temps, P95 small fft w/AVX/avx2 and avx-512 disabled gives a clean, non bouncy, constant 100% load using the same instruction sets games use, so gives a baseline worst case scenario. With that cpu, you can pretty much count on never seeing anything close to the reported P95 temp.

Currently own a Fractal R5, about to retire it though, in favor of a shoebox from Lian-Li/ncase.

 

[Karadjgne]

Meshify C Mini

www.fractal-design.com

Misleading lol, it's mATX...

One thing about the Meshify's, if you are not using the top with any exhaust fan, block off that huge gap. The single rear exhaust pulls in far too much air from outside the case with that big open vent. You'll want to move case air out as a priority, so blocking off the top forces the exhaust fan to only have 1 source of air to draw from, the case.

 

[Darkbreeze]

Umm ram? Should be in A2/B2. From the picture it looks to be in A1/B1, which with Ryzens almost always runs ram at funky speeds.

Besides which, regardless of whether it's Ryzen or Intel it should be in the second and fourth slots anyhow, no matter what board or platform it is. So long as it's a dual channel platform, DIMM slots 2 and 4.

I'd change the slots straight away. Good catch too K. I totally didn't pay attention to it.

 

[GregP74]

Umm ram? Should be in A2/B2. From the picture it looks to be in A1/B1, which with Ryzens almost always runs ram at funky speeds.

Good catch. When I first fired this thing up I was having horrible RAM problems. I'd take the ram out and put it back in and had it in 1 and 3. As soon as I got it back in slots 2 and 4 all was well!