Are all routers really noisy?

sferg410

Hi, finally got my cisco lab up and running, powered it all on and wow what a shock... how much noise do my 3 x 2811's make!! it is like being in a factory... Is this normal or are the fans knackered because the units are 2nd maybe 3rd/4th hand??

Would really like to know as they are really making a lot of fan noise...

clarson

when the units are first powered on, all (3) fans are going wide open. And, they are loud. Once the router is up and running the ios (about 5 minutes), it will reduce the amount of fan that is necessary, and the amount of noise will reduce. But, these routers are designed to be put into a rack in a data closet. Not on someones desk. The same goes for the 3560s. Those fan are going full blast at startup and will back down once they are booted. I think at bootup those 3560s almost make more noise than the 2811s do.

And, no they all aren't that loud. Such as 1841s are a lot quieter. And, so are 3560-8pc, as they have no fan.

theodoxa

Not all of them are as loud. The 2811 is the loudest router I've had in my personal lab. That is why I personally prefer the 1841 when you don't need the voice features of the 2800 series. It is smaller and a lot quieter. On a side note, even the 2811 doesn't hold a candle to my Dell PowerEdge 1950 server. I don't ever turn it on anymore because it not only sounds like a jet engine, but it puts out so much heat it turns the room into a sauna even with the A/C running.

Cisco Inferno

Remember, those fans are meant to offset the heat from enterprise level traffic. In a home lab, you do not have that. you just have your stuff talking to each other. No real need for tons of rpms. You can add a resistor to the wiring OR do what I did, buy silent 40mm fans. The before and after in terms of decibels are night and day.

TechGuru80

As already said...the equipment usually sits in a data center, not in a cubicle or bedroom/office. With that being said, the 2811s that I have are quite a bit louder than my 1841s...I think it's just that model at least.

OctalDump

So the reason that enterprise routers tend to be noisy is that they datacentre costs demand high density, which means making things thin and deep. But they also need to keep cool, so they need to install fans. But the air flow has to go from front to back. So this means that you need to use small fans. The smaller the fan, the less air it can move per revolution, so the fans need to spin faster. Small, fast fans means noise.

The other thing that contributes to noise, is that the as the fans get older, they start to wear out and spin off centre - wobbling. Also as the gear gets older, it tend to get dirtier, which means less effective cooling. Most gear spin the fans faster as they get hotter.

But that means that sometimes you can open up the unit, clean it out, and possibly replace the fans, and it will reduce the noise. There are various options with fans, which I'm not currently up to date with, but you can buy better quality fans that are quieter.

This is true of most equipment designed for putting in a rack. Datacentres are very, very noisy places. A lot of the major datacentres that you can colo at will give free ear plugs if you are going out on to the floor.

sferg410

My 3560's are almost silent Clarson.

sferg410

OK, they are loud generally due to the environment and hard work they would be doing in enterprise. So I am wondering, due to the low level of work etc. they will be doing and maybe only on for a few hours a day etc sat on my desk, windows open, could I not just disconnect some or all of the fans? Surely they don't need that level of cooling for the low level of work I will be putting them through.... Please advise.

doctorlexus

Try to actually put them in a closet. If you live in an apartment, hang a couple clothes lines and move your clothes out of your closet. Then put a rack in the closet (you can make your own out of 2x4's if you have a drill and circular saw), and run a line out to your desktop/laptop. It's easy enough to fix any holes when you move out with spackle and a quart of matched paint.

sferg410

doctorlexus wrote: »

Try to actually put them in a closet. If you live in an apartment, hang a couple clothes lines and move your clothes out of your closet. Then put a rack in the closet (you can make your own out of 2x4's if you have a drill and circular saw), and run a line out to your desktop/laptop. It's easy enough to fix any holes when you move out with spackle and a quart of matched paint.

Nothing like this is an option. They will remain sat on the desk.

clarson

as the fans are necessary for proper operation and people usually are not around to check them, they are monitored for proper operation. So, if you disconnect them. They will be throwing error messages about the fans not working. I've heard that is a way to stop messages from going to screen all the time and being a real pain.

all the fans are one side of the 2811s. So, sitting on the other side of the fans should be less noisy. And, you could make something to "funnel" the noise away from where you are sitting.

run the show env all command to see if the fans are being reported as work properly

OctalDump

sferg410 wrote: »

Nothing like this is an option. They will remain sat on the desk.

Open it up, clean out the dust, consider replacing the fans.

sferg410

None of them are dirty really inside. At this point i have just disconnect all the fans. Will get a 'silent' fan and see what it is like and if any good I could replace with those, problem is the front psu fan, that is double width, that is the one that sounds like a hoover.

fmitawaps

On my 4th 3560 that I just got, I tried an experiment. With the switch on and running (and the top of the case removed), I tried unplugging first one, then two of the fans. I was thinking that they didn't need the airflow from 3 fans. But once one fan was unplugged, the others revved up. So that is no good.


One solution would be to use an 80 to 120 mm fan from a desktop PC, and make a duct to have it blow air through the power supply from outside the case, that ought to be enough to cool it with all the internal fans unplugged.

sferg410

So, does anyone know where you can get quiet number 3/front fans for the 2811? The double width one that feeds air to the power supply.. Sounds like a hoover....?

or

Does anyone know how to turn of the low fan rpm warning messages totally?

Cisco Inferno

sferg410 wrote: »

So, does anyone know where you can get quiet number 3/front fans for the 2811? The double width one that feeds air to the power supply.. Sounds like a hoover....?

or

Does anyone know how to turn of the low fan rpm warning messages totally?

I ordered some Scythe Mini Ultras for my older gear. im sure they have the fatter one you need.


you know... even a new oem fan probably sounds quieter than something thats been running 24/7 for almost ten years.

davenull

sferg410

I have a few 2811s and tried to solve the noise issue a couple of years ago. Overall, for me, it either didn't work or wasn't worth the effort. I bought a few same size lower rpm fans and also some resistor cables. Only one new fan actually spun up, the others didn't. The power supply fan is the noisiest and its replacement fan either didn't fit or didn't work. The cooling design of the power supply in 2811 pretty much requires a high-rpm fan in my opinion.

The resistor cables also caused the new (and old?) fans not to spin at all. It's been a while, I may not remember correctly.

Also, if a fan is not running or running at lower rpm, the syslog will spam you with 'bad fan' messages and it gets annoying.

If you do decide to play with it, you'll have to swap out yellow and black(?) cables on the fans. Google to confirm the colors.

Mind you, I'm not into electrical engineering, so I wasn't measuring any voltage/amps and whatnot. I'm sure more skilled/determined folks can take the motherboard out and build a custom case around it with large quiet fans and neon lights..

FWIW, here are some parts from my Amazon history that didn't quite work:

https://www.amazon.com/gp/product/B00118ZWYY
https://www.amazon.com/gp/product/B006ODM76C
https://www.amazon.com/gp/product/B0016CMCBG
https://www.amazon.com/gp/product/B007PPHLCS


These days, I just play music louder when I lab, it helps.