Is the speed multiplex on a switch

[eden188]

Sorry to sound dumb, but I was wondering if I have a 5 10/100 ports switch, all connected to 100mbs PCs, let say all 5 access big files at the same time. Does the switch splits the speed to 20mbs each, or are they all independant of each other??

Thanks in advance.

[james_d]

That's the main advantage of a switch over a hub; with a switch each port runs independantly, with a hub the total bandwidth is shared amongst them all.

Depends on what you're trying to do though. If your five computers are all accessing files on completely independant computers, you'll get something approaching the full 100Mbits between each computer.

If you've got 4 computers all trying to access files on just one computer (eg a server situation), you'll be limited to the 100Mbits from that one computer, so each machine would only get a portion of this.

[eden188]

Brilliant! Thanks for that james_d. I did remember reading something like that before, but its good to be confirmed. Good point about the server situation, which is what my current setup is.

Current setup:

ADSL Modem
|
10/100 switch ---> Media/File server
| |
| |-----------> 10/100 switch --------------- > HTPC & AV equipments
|
|----------------> 10/100 switch --------------- > Home & Office PCs


Since I have a file server which holds all my media files (especially videos), my concern was that if I have more than 1 computer trying to access the files from the server, would the current 10/100 switch cope? or would I be better off changing this particular switch to a gigabits one, so that the server talks to the new switch at gigabit, then the rest at 100mbs max?

[b0redom]

Not sure that's strictly true james_d - it will depend on the spec of the switch.

The main advantage of a switch over a hub is that only packets destined for the hardware address of the device attached to the switch port will be sent to it.

A hub is like a dumb switch all packets are sent to all ports, which can clog things up a lot.

There will be a maximum throughput for the backplane of the switch which will probably not be 100Mbps * number of ports unless you're using a really high end switch.

[james_d]

Quite, but less of an issue with a 5 port than a 48 though. I deliberately chose not to go into too many details.

Are you just streaming video to the various PCs/Media Centres? I'd just try it with the 10/100 to begin with, the bandwidth of compressed video isn't particularly large - I'd had it running at home with just 10Mbits due to a cabling fault quite happily.

[eden188]

thanks again james_d. It's mainly for video, I haven't set up the streaming service yet on my server, basically it just runs as a file of the server, if that makes any difference. I think I'll play with the 100mbs for a while and save myself a bit instead of wasting on something that I don't really need.

Thanks everyone else for the advice!!

[Splash]

Just a thought before you start splashing the cash - does your file/media server have a gigabit NIC? If not there's very little point in upgrading the switch.

[eden188]

Thx Splash, it does