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Catalyst 6500s are Too Loud...Way to Fix?

I recently purchased seven 6500 series switches, a couple operating with IOS (6509s) and the rest with CatOS (6506s). Each switch has two 3000W power supplies and a fan tray.

Looking at environmental monitoring, the switch is neither heavily loaded (power wise), nor running very hot (~25-30C with input and output temps differing by 2-3 degrees).

The short is that the fans in the power supplies are VERY loud. In fact, they are so loud that I am not going to be able to use at least one of the switches in the location that they need to be, and am likely going to have to return them for a stack of 3750s or something. While this would work, this is not the path I would like to pursue.

Is there any way to put the fans into some sort of variable state where they only run as fast as required to cool the box based on its usage? Other network hardware has this functionality, as do most of our servers that we have in place. The CAT 5509s that are being replaced are not NEAR as loud as these 6506/9s.



Frequent Contributor

There is no way to alter the speed of the fans. There is nothing that can be done about the amount of noise coming from the switch.


Still brainstorming...

If I were to use DC power supplies instead of AC, would they be any quieter?

Its possible the fans are bad, but then your sh environment doesnt show any temperatures problems in the chassis. You could probably open a case with Cisco TAC to get the powersupplies RMAed. The chassis has a fan tray on the side, as well as fans on the power supplies. I am not sure which one is exactly generating more noise...

Sankar Nair
UC Solutions Architect
Pacific Northwest | CDW
CCIE Collaboration #17135 Emeritus

Those units are just plain loud and there isn't alot you can do about it. If you have the Fan Tray 2 installed it's even louder... and if you have Sup 720's you have the Fan Tray 2.


Are they to be sitting in the open? Do they have to be? You could always mount them in a good cabinet, which will reduce the noise drastically, but you must ensure that plenty of cool air is available to the unit.