3900X in NCASE - Air vs AIO

Epos7

Caliper Novice
Original poster
Aug 24, 2019
26
1
I made some upgrades to my NCASE a few weeks ago, one of which was a Ryzen 3900X. I strapped my Noctua C14 to it and started doing some testing.

I'm finding that I hit the thermal threshold of 95C in Prime95 after about 5 minutes. This results in thermal throttling and the CPU clocks down to about 3.5Ghz.

Current configuration:
Noctua C14 with two 140mm fans set to intake
92mm rear fan set to exhaust
120mm NF-A12x25 next to C14 set as intake
RTX 2080 with Accelero III
2 x NF-A12x25 under Accelero III set to exhaust

My experience with the 3900X seems to mirror that of others. An AIO has been recommended to me as a solution.

Before I pull the trigger, I wanted to poll other NCASE owners. I was always under the impression that air cooling, especially by Noctua, could come close to the performance of an AIO. Maybe with the 12 cores on the 3900X we've reached a point where the AIO shows more benefit.

What kind of noise can I expect with an AIO? I've always liked the noise levels of air cooling, but the behavior of the 3900X is quite different than I'm used to. It sees a lot of rapid temperature spikes which causes the fans on my C14 to spin up and down rapidly. I've tweaked the fan curves as best I can and now I only see this when running Lightroom or under heavy multitasking.
 

HyperActive

SFF Lingo Aficionado
Jul 22, 2019
138
58
Prime95 is not made for 8+ cores and so many threads. It gets way too hot. Try aida64 or realbench. Also try rear as intake, I tested for myself and it dropped temps with 3-5 degrees when compared to exhaust (at 38% fan speed since it gets high pitched at higher speeds).
But yes, 12 cores is a bit high for air cooling.
My 3700x gets 85 degrees on aida64 on 80% fan speed I believe. While gaming only 70 with 40-50% fan speed or lower sometimes.
 

judokamak

Minimal Tinkerer
Sep 25, 2019
4
1
C14 should be and is more than enough for 3900 in Ncase.

Here is a guy with the same build:


CPU Temperature Under Load
60.0° C
 

Epos7

Caliper Novice
Original poster
Aug 24, 2019
26
1
Here is a guy with the same build:

CPU Temperature Under Load
60.0° C
His writeup says 65C - sounds like that's his temp after gaming at 1080p for an hour.

I don't have any issues gaming. I think my CPU temp while gaming is probably in a similar range. I don't hear the fans spin up much. Fans go crazy during Prime95 or Lightroom. Gaming they stay at 30-40%.
 

Epos7

Caliper Novice
Original poster
Aug 24, 2019
26
1
Prime95 is not made for 8+ cores and so many threads. It gets way too hot. Try aida64 or realbench. Also try rear as intake, I tested for myself and it dropped temps with 3-5 degrees when compared to exhaust (at 38% fan speed since it gets high pitched at higher speeds).
But yes, 12 cores is a bit high for air cooling.
My 3700x gets 85 degrees on aida64 on 80% fan speed I believe. While gaming only 70 with 40-50% fan speed or lower sometimes.
Thanks, I'll try aida64 and see what happens. I'll also consider playing around with the direction of the rear fan. Could also think about switching the direction of the C14 fans.
 

HyperActive

SFF Lingo Aficionado
Jul 22, 2019
138
58
Thanks, I'll try aida64 and see what happens. I'll also consider playing around with the direction of the rear fan. Could also think about switching the direction of the C14 fans.
Tried it for myself: my chromax a14 140x25 fan underneath as intake was 5 degrees cooler than as exhaust. Though I have read that c14s with 140x25mm underneath and 15mm on top both pushing in the heatsink gave the best result in temps if you have 2 fans.
 

Epos7

Caliper Novice
Original poster
Aug 24, 2019
26
1
Tried it for myself: my chromax a14 140x25 fan underneath as intake was 5 degrees cooler than as exhaust. Though I have read that c14s with 140x25mm underneath and 15mm on top both pushing in the heatsink gave the best result in temps if you have 2 fans.
Interesting, so with two fans opposite directions produce the best results?

I have two 140x25 fans on my C14. Could give this a shot.
 

raymondzzd

Cable Smoosher
Aug 7, 2019
9
5
His writeup says 65C - sounds like that's his temp after gaming at 1080p for an hour.
Correct. Cinebench R20 is at 80-85C. I have not tried Prime95.
I have 240 AIO on my old PC, the pump noise becomes much louder over the years. Louder than the fans.
 

jcadduono

Minimal Tinkerer
Oct 13, 2019
4
2
If you want a reference, running AIDA64 CPU+FPU+Cache stress test on my 3900X in my NCase M1 using H100i Pro, with PBO enabled and +200mhz Auto OC, with AIO mounted as intake with 2x NF-A12x25 inside, on Quiet (900 rpm pump) my max temp is 92C, on Balanced (2000 rpm pump) my max temp is 81C, and on Performance (2900 rpm pump) my max temp is 78C.
I do not use the rear fan port at all, and exhaust via my ASUS 2080 Super using 2x NF-A12x25 on the bottom. I think rear fans create too much noise, maybe due to turbulence.

During 3440x1440p gaming, my CPU temps max at just 65C on the Quiet setting of the AIO, but honestly most of my games are only using 1-2 cores for heavy loads. The Balanced setting is audible (the fans are inaudible but the pump does start to make some noise beyond 1200 rpm)

I LOVE this setup as I can easily game on Quiet which the fan and pump noise is COMPLETELY INAUDIBLE from 1 ft.
Not only that, but the bottom exhaust heats my hardwood floor next to me which is great for my feet during the winter. ;)

I am using a Crosshair VIII Impact and the chipset fan is much louder than the Noctuas or pump, so I replaced the thermal pads on the chipset to reduce it 20c and then removed the chipset fans. I believe the AIO intake is actually enough to keep the chipset cool with passive heatsinks on this board.
Keep in mind that the chipset fan isn't really loud at all, but I am very sensitive to noises, so this is saying something as to how well these AIOs work on Quiet mode. :)

Understand that an AIO adjusts fan and pump speeds based on the liquid temperature which changes very slowly and not the CPU temperature, so there will be no audible fan spikes ever. I can certainly recommend the H100i Pro over any air cooling solution in the NCase.
 

Epos7

Caliper Novice
Original poster
Aug 24, 2019
26
1
Thank you for the detailed notes, much appreciated.

I'm going to run some more tests over the weekend to see how my air cooler is doing. The lack of audible fan spikes with an AIO is appealing.
 

HyperActive

SFF Lingo Aficionado
Jul 22, 2019
138
58
It's true that my c14s and 3700x while gaming is much lower than a high cpu load. Only stock strix at 40-50% is audible, cpu fan isn't. Don't know temps and fan speed while gaming with a high cpu load game (ac or tomb raider).