Slightly OT: Ethernet switches

Jul 09, 2011 26 Replies

Isn't Ebay a wonderous place? I was looking for a 4-port 10/100 Fast Ethernet switch, maybe an 8-port, although I can't see that I'll need more than 4 to be honest. Anyway, the surreal world that is Ebay means that I won a 24-port D-Link DES1024R for just a couple of quid more than a domestic consumer-level 4-port switch went for! :)



It seems to work well and does what it says on the tin, but the fan is bloody noisy. Given that this is designed to be rack mounted amongst other heat generating equipment (which it won't be here) and perhaps have all 24 ports in use, I can see the need for a fan. However, as I'm probably only going to use four or five ports, I'm thinking it should probably be safe enough to disconnect the fan - what do the panel think?



Thanks


Mmmmm - the manual says it can draw 24w, which is a lot of heat to dissipate. If you could drill a matrix of cooling holes in the case then you might get away with fanless.

I have a similar 16 port switch in the loft which appears to be passively cooled, so it can't be impossible.

IME, such second-hand items on eBay go for more than they cost brand new. A 5 port 10/100 switch brand new would be under £10 from a computer fair, probably as low as £5 nowadays (a long time since I bought anything less than gigabit).

There's a glut of secondhand large rackmount 10/100 switches because companies have upgraded to gigabit. These 10/100 switches don't even sell at £5 at computer fairs. (Maybe a managed one would.) Often they are actually a 10 hub and a 100 hub, with a 2-port switch between the two internal hubs, although the one you have looks like a modern design (insofar as any 10/100 switch can still claim to be modern).

In answer to your question, I doubt the power consumption varies much according to the switching load, so it probably will need its fan.

Leave it running for a bit and see how warm it gets. If it stays cool, then knobble the fan (or find a lower voltage supply for it in the box).

Note however these can do strange stuff when they get too warm! I had one apparently fail altogether on a lan - refusing to pass packets at random it seemed. Tried resetting etc, no difference. So swapped it out for another. When I tried the "faulty" one later it seemed ok again - presumably after it cooled down.

(how much did you bid for your BTW - just working out if its worth flogging that spare I have on the shelf!)

Cheers all, thanks for your help. John, including postage I got it for just over 12 quid.

Slight OT, but how does "Computer Exchange" (CEX) work ? All the second hand items there are about 5% cheaper than new ...

I did on mine, and it's still fine a couple of years later.

Their customers are almost entirely chavs, thieves and doleys, like Cash Converters.

that its power consumption and heating bears no relation to how many ports you use.

Do search on an item say HTC Desire HD, they buy at =A3140 ish and sell at =A3280 ish (Grade A locked) or =A3157 v =A3315 (Grade A unlocked).

Unless someone here knows the beast from new and can tell you the fans are always noisy, it may just be age. Try oiling it (often there's a sticky label covering the bearing on the rotor) or replacing it with a modern equivalent.

Chris

Main problem with these are the fans are pretty small, and spin fast.

Not always the case. A friend has a Cisco switch that has run fine without fans for a couple of years in his hallway :-)

If you load up all the ports and run them then it definately needs cooling. With just a few of the 24 in use it runs cool.

Darren

Not always true. As I say elsewhere, I know of a Cisco switch where that is definately not the case - and HP procurves at work will run and run with dead fans if they are not busy. On busy bits of networks they definately do not...

I all seems related to CPU load which I guess makes sense. Of course, if the switch we are talking about is a dumb unmanaged switch then the CPU is probably less relevant and you are correct.

Darren

Aye, it looks like a 1U high unit so the fan, to shift any quantity of air, will be really whizzing round. Small and fast = noisey, large and slow = quiet.

Fully loaded up the number of blinken lights will be higher so there must be an increase in power consumption for them. How much is debateable, LEDs seem to require 4/5ths of F.All current these days to blind you...

Only the mearest hint of a very light oil. Sewing machine oil or similar.

1 U height or rather 40 m x 40 mm fans are usually very noisy. RS do some Papst ones that are quieter than those from Taiwan but there is a limitation as to how much air you can shift by the size and thats one of the problems with small fans..

Drill the top with a series of vent holes, and mount a 120mm fan bolted onto the outside of the lid...

Having had the slightly more expensive version of that (managed) fail on me in a remote data centre, I think you should bin it, go to your local computer shoppie and buy a small 5-port Gb switch, which you can probably find for under £20 these days.

Gordon

... or take the fan out. Drill holes in the _ends_ of the case, and stand it on end. The heat should act like a chimney. And if it goes pop - well, follow Gordon's suggestion :)

Andy

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