SM 846 fans, what's really good enough to cool a full rack without going crazy from noise?

Notice: Page may contain affiliate links for which we may earn a small commission through services like Amazon Affiliates or Skimlinks.

klepp0906

Member
Feb 10, 2022
40
0
6
Aaaaaaand for my first post ;p

So i've finally procured my first DAS. I've been going through it bit by bit trying to polish it up before i start the arduous process of setting it up and putting it to work. I currently will have 20 of the 24 bays full (not long for the last 4 either im sure) with 7200rpm disks.

Noise is the primary concern as its going to be literally 4 feet away from me. I cant have acoustics as the only concern though as it will be situated in my upstairs office which can get relatively warm in the summer months. we keep the thermostat at 72 but thats the downstairs temp lol. I'd have to imagine its at least 3-4 degrees warmer up here.

Basically want to have my cake and eat it too :( I know i can make it quiet as can be, but it would be at the expense of letting my drives cook. Ive spent an entire day and a half going through these forums, reddit, google itself and while ive came across the popular options, i dont feel any closer to making a decision so I finally caved and posted.

I see people use the noctua A8's. While i can get on board with the pricepoint considering how much ive already sunk into this, i cant help but feel like they wont cool nearly well enough. Anyone using 5 of these for the fanwall+exhaust with a full rack of 7200's and still able to keep em under 40?

I also see a lot of the FAN-0074L4 x3 + FAN-0104L4 combo. i'm unsure of the viability here as the fanwall fans seem like theyre a minor decrease in db but also a decrease in static pressure.

lastly some guys have went with 5 of the FAN-0104L4 which seem to be basically the same thing as going 5x noctua A8 except for more expensive.

I did already purchase a pair of 920SQ PSUS to replace the 721P's this came with but im entirely stuck on the fans. its the last purchase and i'll be done.
 

i386

Well-Known Member
Mar 18, 2016
4,240
1,546
113
34
Germany
I also see a lot of the FAN-0074L4 x3 + FAN-0104L4 combo. i'm unsure of the viability here as the fanwall fans seem like theyre a minor decrease in db but also a decrease in static pressure
The noctuas are even worse in terms of static pressure.
Personally I would not use anything that moves less volume and has less static pressure and even this setup can lead to hdd temps of 50°C or higher under load with ~20°C airintake of the serverrack/enclosure.
 

Stephan

Well-Known Member
Apr 21, 2017
923
700
93
Germany
19" in 4U AND quiet has always been a problem. Have you done STL-Datei Supermicro SC846 120mm Fan Shroud herunterladen • Design für 3D-Drucker ・ Cults?

24x 7 watts is only 168 watts to get rid of. So for HDDs alone even slow and quiet 1500rpm Noctuas would do it. Check with a smoking wood stick how well air is sucked into each HDD front side. If at say 3 cm distance smoke is already nicely sucked in everywhere, it will be imho enough for the HDDs. Also check Safe HDD Temperature Range to Avoid Hard Disk Failure for some tips.

Question is, are you using the original fan baffle and the original copper passive CPU cooler which runs to the back with two screamer fans on the backside? If yes, you need to keep the loud fans, because otherwise the CPU will not see enough airflow to cool 200 watts TDP. If mainboard uses a dedicated cooler instead, the case can be switched to quiet BeQuiet or Noctuas.

Make sure any SAS controller remains properly cooled though. I presume you will be using Linux. smartctl temp readings, lm-sensors or IPMI will be your friend. Stick a plastic NTC temperature sensor connected to suitable USB electronics between PCB and heatsink of SAS controller and when temperature does not go up significantly when putting load onto SAS drives, you're good.

Edit: If you find nothing else, something like Digital Thermometer -55 – +125°C with USB connection (no affiliation) should work to observe SAS chip temps.
 
Last edited:

klepp0906

Member
Feb 10, 2022
40
0
6
19" in 4U AND quiet has always been a problem. Have you done STL-Datei Supermicro SC846 120mm Fan Shroud herunterladen • Design für 3D-Drucker ・ Cults?

24x 7 watts is only 168 watts to get rid of. So for HDDs alone even slow and quiet 1500rpm Noctuas would do it. Check with a smoking wood stick how well air is sucked into each HDD front side. If at say 3 cm distance smoke is already nicely sucked in everywhere, it will be imho enough for the HDDs. Also check Safe HDD Temperature Range to Avoid Hard Disk Failure for some tips.

Question is, are you using the original fan baffle and the original copper passive CPU cooler which runs to the back with two screamer fans on the backside? If yes, you need to keep the loud fans, because otherwise the CPU will not see enough airflow to cool 200 watts TDP. If mainboard uses a dedicated cooler instead, the case can be switched to quiet BeQuiet or Noctuas.

Make sure any SAS controller remains properly cooled though. I presume you will be using Linux. smartctl temp readings, lm-sensors or IPMI will be your friend. Stick a plastic NTC temperature sensor connected to suitable USB electronics between PCB and heatsink of SAS controller and when temperature does not go up significantly when putting load onto SAS drives, you're good.

Edit: If you find nothing else, something like Digital Thermometer -55 – +125°C with USB connection (no affiliation) should work to observe SAS chip temps.
thank you for the reply. I would have gotten back sooner but apparently didnt get notified via email on this one. while this is my first EVER foray into server chassis' and such i'll purely be starting out as a JBOD box and on windows using drivepool+snapraid. That being said, when i get more comfy with some of the terminology and tech and workings I do intend to most likely convert it into a NAS. This means id rather not change the fans twice. I dont have the shroud that is used presumably to aid in passive cooling, and i cant begin to guess what route i'll take when/if the time comes, but ill source one if necessary.

funny you linked that fan shroud. I actually did come across that in my practically perpetual research and it just finished printing. While it cost virtually nothing, I'm wondering if using that metal one everyone likes to source (norco fanwall bracket i think its called?) is superior? apart from it being metal vs plastic, I'd prefer the "less" janky option and considering the printed one seems to screw in and mount at all the same points the stock one does, I dig it.

so is the best route to cutting noise but keeping good cooling going to be putting in the printed fan shround and using high static pressure low rpm 120mm then? I assume for the exhausts I would just source some equally quiet 80mm and put them in the hot swaps that are present?
 

Stephan

Well-Known Member
Apr 21, 2017
923
700
93
Germany
Ugh, Windows. Ugh, snapraid. Ugh, snapraid with this many drives. ;-)

At 24 drives total I would do two 12-disk RAIDZ2 (for smaller <4TB disks, less rebuild time necessary) or two 12-disk RAIDZ3 ZFS VDEVs on Linux. Both added to a single zpool. You will gain snapshots, live and always valid RAID for better uptime, checksums for data+metadata, transparent compression, no more fsck, no RAID5 write hole, etc. It's just the superior solution. For dimensioning check out Edit fiddle - JSFiddle - Code Playground and also How I Learned to Stop Worrying and Love RAIDZ | Delphix

What motherboard and what CPU fan are you going to use? Rest of cooling solution needs to take this into account. 3D printed holder enables slower RPM = quieter 120mm fans and also enables more options for such fans.
 

klepp0906

Member
Feb 10, 2022
40
0
6
LOL hi again, be easy. dont make me regret the fortune i spent getting this all off the ground. At current i'm literally using a bunch of internal drives, and a bunch of external usb enclosures with individual drive letters all but used up.

baby steps! Linux is like chinese to me, outside of curiosity compelling me to poke around in a VM i know nothing of it. I do know that there are more popular solutions surrounding some of the non ntfs file systems and linux based softwares etc, perhaps one day. A big (HUGE) perk for me with drive pool is it necessitates no formatting. I have 100TB of data at current im not willing to lose and drive pool literally lets me create my pool(s) and lose no data.

As for motherboard and cpu/fan, none. it will be connected as a dumb box via CSE-PTJBOD-CB3 to CableDeconn Dual Mini SAS SFF-8088 to SAS36P SFF-8087 Adapter to LSI SAS 9207-8e HBA

In the future I may graduate to turning it into a NAS perhaps, but i'll likely use a CPU with an active cooling solution. It seems (while i dislike the jankiness and losing the hotswap'iness) that putting some 120mm noctua's in may retain its stock cooling capacity more or less while decreasing the noise. trying to keep the whole box 45db or less as that appears to be what my office is currently at with the pc's in it and im either comfortable with or acclimated to it :p
 

Mymlan

Clean, Friendly, and In Stock.
Oct 1, 2013
32
73
18
I use a couple of SC846s with sets of Noctua iPPC 2000 fans. They have great static pressure and airflow for the noise, much more than the standard Noctua line. If you remove the default fan wall, you can ziptie three 120mm fans together in its place. For DAS chasses, you can run a second set near the rear.

It is worlds quieter than the stock fans or anything else you'll be able to fit in those 80mm brackets.

SC846.jpg
 

klepp0906

Member
Feb 10, 2022
40
0
6
thanks for the pic. yea thats the way im leaning, gonna get 5 of the 120's and hope the ones on the rear with the 3d printed adapter i found doesnt impede too much if i need to convert it to a NAS in the future. For now its just the cb3 power board in that area so i should be okay.
 
Last edited:

gb00s

Well-Known Member
Jul 25, 2018
1,188
599
113
Poland
Get any 120mm on the front of the case (caddies) and install 120mm Noctuas in the case. This way the disks are way cooler and you can turn down rpm of both fan lines (in front of the case and in the case). Less rpm = less noise of course. There are also 3D print templates in the internet for these 1200mm solutions in front of the case.
 
  • Like
Reactions: richard.dzavoronok