Originally Posted by
PTravel
I saw a couple of surprisingly inexpensive 10GB switches on ebay last night (though I'm too broke to get one this month
). Now I'm confused about cabling. I see there's a whole variety of different connectors, apparently depending at least partly on the physical cable (fiber optic, copper, etc.) selected. I was hoping for something that would simply be backwards compatible and use RJ45 and Cat6 (or Cat6a) but, apparently, it's going to be more complicated than that.
10GB is appealing to me because I often move lots of data around my system and it would be nice to accomplish in seconds what currently takes minutes. I may have to wait, though, until the various standards shake out and a "preferred" one emerges. Then again, my first LAN was 10 Mbs, so I shouldn't complain about my 1 Gbs setup.
There are only two connectors for 10GbE in production and worth considering -- fiber (SFP+) and copper (RJ45). Both are backwards compatible with gigabit ethernet, but unless you have fiber (SFP) gigabit, the former being backwards compatible is unhelpful.
(There are also two obsolete ones: CX4 aka "infiniband" cabling, which is only useful over very short runs, and XFP which is an obsolete standard for fiber transceivers.)
Fiber is more common on the used market, and until recently was much cheaper. This has changed; the cheap Netgear switches are copper rather than fiber. The other thing is that with fiber, you need transceiver modules or special cables, which may or may not have ended up saving money (a lot depends on whether the manufacturer allows "passive" cables or not, and whether they lock to approved -- and much more expensive -- transceivers. Name-brand Intel transceivers were $250/each last I checked; non-brand from China were $99 for a pack of 4.) One thing I liked about the Dell-branded switches is they worked with absolutely anything cabling and transceiver-wise.
If you were doing especially latency-sensitive storage or high performance computing application, fiber also has lower latency, but the difference is an irrelevance in any normal application and is mostly relevant when comparing to like Myrinet or Infiniband.
Copper/10GBase-T will definitely be easiest for you, and if you were buying new, wouldn't be too bad of a premium. I see a lot less of it used.