Gigabit ethernet gets real
Posted 2/10/2005
For several years, those of us with home networks have been running
10/100 mixed LANs, usually with switches here and there. Works, cheap,
reliable, easy to wire. Very few indeed have home gigabit; the adapters
are cheap but switches have been very expensive.
However. That's no longer the case!
Goals
Cheap, reliable, low-power, no
cooling fans. Oh yeah, I want fast, too, so we need jumbo frames
(9000 byte packets instead of 1500; makes a huge difference in
performance) and a fully non-blocking switch.
This is all on twisted pair, indoors, for home use.
For my network, I need 8 port switch; you may be able to get by with
less.
Cut to the chase!
If you need 8 frames, the best option I've found is the SMC
8508T (Amazon, non-affiliate link). $100, jumbo frames, 15W power,
no cooling fans, 16Gbit bisection bandwidth, decent blinky lights:

If you can live with fewer ports, the otherwise-identical 5-port
version is the SMC
8505T (Amazon again) for $67:

About the only disadvantage of either one is that they use a wall-wart
power supply instead of an internal. On the plus side, the do come with
both rubber feet and rack ears. These are both really nice little
switches in my opinion.
Which network card should I buy?
For network cards, I like the 3Com
996BT (ZipZoomFly), about $60 from various venders. The Intel
Pro 1000/XT (130, ZZF) is also supposed good and reasonably cheap.
If you've got the cash, the best
card is the SysKonnect
SK9821 (Froogle, appx $100). To get good throughput, PCI-X or 66/64
is pretty much required. Otherwise, you'll get 2-3X faster than fast
Ethernet at best.
Given that the SysKonnect prices have fallen fast (they used to cost
$500) I'd recommend the 9821. I ended up with 3C996's, since I bought
them a while ago when SysKonnext cost 6X more. Note that the 996 is
actually a Broadcom chip, and uses the Tigon 3 driver (tg3) in Linux.
Many motherboards now have gigabit included on them as well. Bonus,
that.
Read For Yourself
This page represents quite a bit of research for me, and I've just
presented my conclusions. However, you don't have to take my word for
it!
Things To Watch Out For
- It's pretty much impossible to tell online if a switch has
cooling fans or not. Since most of them use the 40mm size, they make
lots of noise and fail quickly. Google, or check it out in person. I've
gotten a lot pickier about noise of late, so this was a showstopper for
me.
- Not all jumbo frames are created equal. Vendors have been know to
call 82 extra bytes a jumbo. You want 9000 or better.
- My Dell Optiplex GX280's came with an onboard Gig-E card, a
Broadcom BCM95751. It uses the same driver as my 3C996, but can't do
jumbo frames! I have the same machine under XP, and no jumbo there
either. Hardware limitation.
- Despite having gigabit on their laptops years before anyone else,
Apple Powerbooks do not support jumbo frames.
- No, this will not speed up your DSL connection.
- If the first speed test you try is scp/sftp, you'll be disappointed.
However, PSC has a 7-line patch to scp that speeds it way up. Like 10X faster. Go and get it.
So why bother?
High geek value.
It is faster, after all.
You can beat down anyone who complains about lag at your next LAN party.
Most importantly: The hardware is now down around the cost levels of
slower 10/100 gear, so there's no reason to pay 10 bucks less on a
switch when you can get gigabit.
Go for it.