Taming the noise on the SuperMicro
The SuperMicro SC835 chassis I picked up a while back has been annoying me with noise lately. I’m trying to hold out because we’re hoping to buy a house this year, so if we can do that and I can put the server out away from everyone I won’t really care about noise. But oh my god is it infuriating lately!
I spent some time over the last couple weeks playing with a few different ways to poke fan control signals into the X8DAH+-F motherboard, to no avail. After reading a bunch of forum posts and some code of questionable quality, I found someone with a similar issue as mine and the developer’s response was “just use some low noise adaptors” and it seemed so obvious.
Since Duncan’s PC needed one of the cheap fans in it replaced (it started groaning) and so I had to place an order to PCCG anyway, I decided to pick up a pack of three LNAs. Since I already have two that came with my fan that’s five which is the same as the number of fans I have, so it was a no-brainer! I’m not sure whether the fans have too much current draw for the LNAs, but we’ll see.
While I had it apart, since I’ve had no bites on trying to sell the PowerEdge R510, I figured I’d knock the X5650 CPUs from it. I pulled out the E5540s from the SuperMicro and swapped the 6-core units in. The slightly newer CPUs run significantly cooler and the performance is actually greatly increased!
So between that and the lower fan speeds, by far the loudest thing in the machine is the PSU, which for not a lot of money I can replace it with a 920-SQ PSU and eliminate that issue as well… so I think I’m going to do it.
Update 2021-02-04: I looked up the specs for the LNAs (probably should have done that before I bought them to be honest), they’re good for 2.5W. By my calculations, the worst of the fans are capable of doing about three times that. Since they’re just resistors, it seems likely that overheating is the most common failure mode, so instead of tucking them out of the way I made sure they were in line of the fans, and we’ll see how long they last.
I caved and spent $99AUD on a “Super Quiet” PSU for the machine (full part number is PWS-920P-SQ), and it’s made a huge difference. The fans in the machine are now definitely the loudest thing in my office, but even they’re fairly quiet. It’s hands down quieter than the R510 even at idle, and the high-pitched whine portion of the noise is mostly gone, which makes a significant difference to the livability of the room.
Update 2021-02-05: Unable to leave well enough alone, I took another look at the output of
sensors and noted that what I originally thought was the ethernet adaptor is actually the chipset. It was running at a toasty 80C most of the time, and occasionally hit 90C (with the configured redline being 100C and critical being 110C). Once it dawned on me that this thing was genuinely hot (I figured it was just a reporting error, as I thought it was the Intel ethernet adaptor which sits idle, and could probably be removed), I scrounged up a couple of 92mm Foxconn fans I had laying around since forever, sat one on top of the two chipset heatsinks and the other pointed at the HBA and the temps dropped significantly.
After this, the chipset’s hovering around 50C (with around a 24C ambient temp and almost 30C in the case). Everything else is happy, including the drives (which I was worried about with lowering the fan speed of the front fans). But jeeze, knocking 40~50C off the chipset, what a difference! This appears to have been what was causing the fan ramp up/down in the mornings and allowed the machine to permanently drop the fan speeds to the morning speeds, which is great because it’s whisper quiet at that point. So as long as the LNAs don’t burst into flames I’m pretty content for right now.
Will I go further and replace the fans in the fanwall? We’ll see, particularly in the colder weather I don’t see any pressing need right now… though if the LNAs start burning out I may need to reconsider that rather quickly. I’m still not sure whether to simply buy five Noctua NF-A8s (they don’t have near the static pressure the current fans have, but I’m honestly not sure I need it), or to drill out the rivets on the fanwall and replace it entirely with something that allows larger fans.
To be decided…