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ML350p G8 - Fan Noise

Occasional Contributor

ML350p G8 - Fan Noise

Hello All, 


We took delviery of a brand new ML350p G8 last week, and ever since have been inundated with complaints of noise! We've run the latest SPP etc through the server and still the fans sit at 33%. 


The server has 1proc, no PCIe or addtional cards and 96GB/ram. It's running ESXI 5.5 (the custom HP version) 


We used to have a G6 in this office and it was almost silent in comparison. 


Does anyone have any ideas?! 



Regular Advisor

Re: ML350p G8 - Fan Noise


Which version of the SPP you used, the latest is 2014.06.0


Try to run offline diagnostice from the SPP cd and see if any errors detected on the fans or other sensors, also attache it here if possible.



msh_it | UAE | AbuDhabi

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Respected Contributor

Re: ML350p G8 - Fan Noise

Are all the fans at 33%, or are there maybe one or two running even faster?

If they're all at 33% or so and the noise is too much, there's not much you can do. HP servers are loud even when the fans are spinning relatively slow.

Of course "loud" is a subjective term. The variables would depend on how close someone is to the server, whether there are any obstacles or partitions in the way, doors, etc. and also the people themselves since loud to one person could be okay to someone else.

This is why people generally put servers into dedicated closets or rooms, because they do get noisy. Of course then you need to provide adequate ventilation into any room you put them in. Nothing would kill a server faster than shoving it into a closet with no air exchange... the heat would build up and the server would spin those drives at 100% until finally it does a thermal shutdown.

If I were in your position, I'd have 2 options:
1) Get a quieter server
2) Put the server in a dedicated (and somewhat soundproofed) room with proper ventilation.

FYI, I just looked at the quickspecs for the ML350p Gen8 and I have a hard time believing the noise level specs. 22 dBA... really? At idle and at load? That doesn't seem at all close.
Honored Contributor

Re: ML350p G8 - Fan Noise



Look at the internet, several similar problems exist, so far no real answer found yet... HP?


I have 5 servers here ML350p Gen8. 4 of them are completely silent with fans around 20%, 1 of them is at 33% and lots of noise.

Why? No idea... Similar servers with similar firmware...


So still waiting for the solution from HP...





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Respected Contributor

Re: ML350p G8 - Fan Noise

Fortunately most people who buy servers don't have them where people are sitting and working... they get stuffed into server rooms where any amount of noise they put out is drowned out by the deafening sound of other servers and CRACs.

Maybe there is some issue with the fans or maybe it's an issue where some zones of the internals run hotter in server A than the exact same configuration on server B.

Array controllers, for example, can run pretty hot... that's the zone where I see the most heat usually, even hotter than the CPUs.

I'll stick by what I said though, HP Proliant fans are loud. I guess I've never had any that ran at less than 33% or so even with cold air blowing in the front of it, so I can't say if they actually do get much quieter at 20%. But at 33% or more, they're power hungry noise makers. :)

The question isn't so much the fans then, but why does the system think it needs to run the fans faster on any given system? I don't know what temp "breakpoints" HP has for going from 20% to a higher speed, but there's got to be that one extra degree F where it says "Okay, I'm going faster", and if they use hysteresis, which I'm sure they do like any thermostat, it probably doesn't slow down again until that temp drops by 5 or 6 degrees F. Otherwise the fan speed would oscillate up/down/up/down.

So unless you could be sure that on 5 servers, the ambient temps and temps in all the zones are identical, and the workload is the same, they're really not identical. Remember that all the air coming in goes over the hard drives, so something like increased disk I/O is going to raise the temps across all your zones.

I guess if I were in that situation and I were curious enough, I'd point a fan at the front of the server to get air moving better across/through it, or maybe even a portable AC, and see if extra cooling actually helps at all.

Otherwise I'd just chalk it up to "servers are loud" and be done with it. :)

I understand some folks need a the power and reliability of a server but don't have the luxury of a server room to put it in, away from people's ears, but knowing those situations exist doesn't change the fact that servers are still loud in general, at least the fans that HP uses.

Fans can either push a lot of air or be quiet, not usually both at the same time. If HP really wanted, they could probably source a quieter model of fan but I doubt their customers are really clamoring for that in general. There *are* some really good and quiet fans out there that have high CFM and low dBA... I use them in my desktop along with liquid cooling.

Imagine if HP introduced some liquid cooling features to move heat away from internal components...that'd be nice and you could have a really quiet server, but again, their typical customers aren't that concerned about noise and it would increase the cost, so... Still, it'd be a cool option (pun intended).
Honored Contributor

Re: ML350p G8 - Fan Noise

Maybe you should check out this video:


HP goes very far (compared to the competition) in cooling in their servers... One example is the 3D sea of sensors...


And for my case I have no disks in the front, I have VMware running on SD cards... 1 CPU 4 DIMM's... So not that much in there... And identical... And 4 servers with fans around 22 to 25 and 1 with 33... Same firmware settings and so on...


So it remains strange and more a server problem and not an HP problem...


FYI I have several servers installed in customer offices which are completely silent. I agree G5 servers and before were noisy but from G6 on they are rather silent...

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Respected Contributor

Re: ML350p G8 - Fan Noise

Maybe it is some hardware glitch on some models then. If the temps are the same in all the zones but the fan speeds are doing different things based on those same temp readings, it makes me think that the temp reading alone isn't what controls the fan speeds. It could be weighing other factors (no idea what though).

One thing is for sure though... HP (or other server makers) don't really seem to spend much time considering the noise levels of their boxes. Power consumption, physical size, cooling efficiency, sure, but besides variable speed fans with more than a couple RPM set points like their past models, they're still just as loud at full speed as they ever were, maybe louder.

So maybe there is a niche market there for quiet servers, just like there is for quiet desktops (media center PCs for instance...totally fanless or super low noise). I have a couple super quiet fans cooling a stereo component cabinet... they're very large fans so they can turn at a relatively low RPM and still have high CFM.

In HP's defense though, moving large quantities of air through the small size of each fan doesn't lend itself to low noise. You move that much air through a small baffle and it'll be loud even at lower speeds. Given the small size of the fan modules (and some of them are dual fan push/pull), the sound levels are a function of the air flow and volume.

I guess we should be glad the fan itself isn't noisy with loud rattles or annoying hums... it really does seem to be nothing more than the air itself churning inside.

I suppose they could try and get a more laminar air flow which, in theory, would be quieter, but I think they already try to direct the air flow as much as possible using their baffles and case design.

But this all goes back to my original point, that most customers don't care if it's 40 dBA or 70+ dBA because it's in a room filled with other servers, lost in a sea of other noise.

About the best compromise I could think of, with the hardware design the way it is, would be to let customers set their own thresholds for what temps will cause what change in fan speed.

For example, if a customer wants to let the internals run a little hotter in order to keep the noise levels down by running the fans slower, maybe they should be able to. Would that void warranty? Most probably, since heat is a component killer, so I don't know if that's really a viable option for HP to provide. Maybe some skilled hacker who really has an interest in quiet Proliant servers could find those set points in the BIOS and modify them... I'm just assuming it's possible to change those in the firmware. Again, I don't think most Proliant customers care that much.
Occasional Advisor

Re: ML350p G8 - Fan Noise

I Had the same problem - it was solved by installing at least one HP hard drive. I tried using a 2.5 inch third part hard drive and it caused the fan behind the drive array to ramp up to 30% again. This is not the case when using SSD drives, however.  Now the server sits at 10% on all fans. which is very quiet.