It happened that I noticed the network speed from my home desktop wasn't close to half of what I expected. A test from another, directly connected PC showed that the Internet speed was delivering the rates I expected. I spent way too long trying to figure out the head-slapper to blame.

Of course, the router that most of the network used to connect to the Internet has only a 10Mb/s port! Doh.

I poked around a little bit and finally broke down and got a cheap Netgear 4-port 10/100 that has a 10/100 WAN port, too. Most do these days, so that just goes to show how long I've had that gateway.

I pulled the new one out of the box, and before plugging it in place of the old one, configured it to be the same. That gave me a slight moment of WTH as the static IP I used evidently caused a conflict on the Internet router to which I connect; I changed the IP to another open IP I have, and the Internet returned.

Frustratingly, speed testing from the Mac showed even worse performance than the tests I ran before! I rearranged wires and restarted all of the network gear, but no improvement. I re-ran the speed test on the original PCs, and both showed the expected peak speeds.

I guess it's the wireless connection to the Mac. Either the WiFi can't handle the extra speed (although Network Utility shows an 802.11n connection at 54Mb/s), or the WiFi is only connecting at 10Mb/s. For the curiouser among you, Firefox wins sporting over 9Mb/s, with Chrome coming in over 8Mb/s, and Safari barely passing 7Mb/s, all running as the only app, with only the tab to SpeedTest.net open!

The WiFi router has 10/100 ports all 'round. It's in the middle of the network, so only LAN ports are connected. Checking the GB router to which the WiFi is connected, it's a 100Mb/s connection, so I'd expect it to be faster.

A little mystery remains, but at least now I'm not waiting as much on the wired connections, no matter which PC is used.