Computer science Random

Ten gigabit home networking

This will be a series of posts. I upgraded my NAS to a model with dual 10G ports, and the compute server already had 10G so I had an excuse.

Old setup – 4-bay Synology DS416play and a USB3 drive caddy for a temporary backup solution. TP-Link 16 port switch, all ports in use.

After some searching, I found this Mikrotik switch for $142 on Amazon. 28 ports of 1G plus two 10G ports. Most switches with 10g are either $100 per port or have fans – this one is 19 watts, no fans, and cheap. Note the “sfp+” notation – it means you need more pricy bits to finish the job, but you can use other media like fiber optic links. So total cost of almost 2x.

Switch in and waiting for NAS backup to complete:

Power usage went down by 20 or 30 watts. Always something I pay close attention to. Here’s semi-final:

Next week I get the SFP+ transceivers and rewire a bit. Trunked dual 1G links for now. Power usage is back to where it was, maybe down a watt or two. The new switch is only 19W (the old was around 30) but the larger NAS uses more power, so even under heavy load with 5 disks going.



I like having ways to see and measure things. Here is my server build:

Here is a simple AC wattmeter showing its consumption:

And here’s the system in infrared showing hot spots:

Measure and don’t just guess. More on low power Linux to follow;).


Power and energy consumption

I built a system that uses a ‘Raven’ Zigbee USB radio and Raspberry Pi to monitor our SDG&E electric meter, and layered Flask and D3.js on top to display usage.

Sometimes it looks quite cool:

Screenshot 2018-07-18 07.21.01.png

The baseline for the house is 225 to 250W, and the plateaus are the (high efficiency energy star) refrigerator. You can see where I got up, turned on lights and cooked breakfast, too. (Electric range and kettle.)

I’m pretty pleased with our usage and have put quite a bit of effort into reducing our consumption. LED bulbs, of course, but also low power servers and networking (61 watts total!), timer switches on idling electronics and measuring what things use. In-wall insulation is also a huge win year-round.

The code is at this GitHub repo if you want to roll your own.

It’s a weekend or two, but if you’re willing to puzzle it out, the data is nice and it’s purely local – no internet connection needed, no holes in your firewall, no sharing of the data. A few minutes reading should be convincing on why that’s worthwhile.