Since a while I’ve been monitoring the power consumption of devices in my home using a power meter from BespaarBazaar.nl (advised by Remi). This power meter is a good one because it is very precise. It starts measuring at 0.2 Watt.
I needed an Ethernet switch to connect my TV, NMT and PS3 to my home network. While searching for a proper switch, I came across DLinkGreen.com. It looked promising. The Green Calculator, a 8.7MB Flash app which is using a lot of CPU (hello D-Link! is this Green?!? what about HTML5?), showed me I could save 70,98% of energy (2h, 1-5 ports > 28.7Wh D-Link Green vs. 99Wh Conventional per day) using D-Links Green technology.
I couldn’t find any green switches from other manufacturers so gave it a try. I bought a D-Link DGS-1005D. It’s a 5-ports unmanaged Gigabit Ehternet switch, supporting IEEE802.3az (Energy Efficient Ethernet), IEEE802.3x (Flow Control), 9000 bytes Jumbo Frames and IEEE802.1p QoS (4 queues).
So I did some tests using the power meter. As reference I used a HP Procurve 408 (8 ports 100Mbit switch).
HP Procurve 408
| Port # | 1 | 2 | 3 | 4 | 5 | … | Watt | 24h | 2h + 22h idle | kWh annually |
|---|---|---|---|---|---|---|---|---|---|---|
| Adapter | 1.4 | 33.6 | 33.6 | 12.264 | ||||||
| 4.4 | 105.6 | 105.6 | 38.544 | |||||||
| m | 4.9 | 117.6 | 106.6 | 38.909 | ||||||
| m | m | 5.4 | 129.6 | 107.6 | 39.274 | |||||
| m | m | m | 5.9 | 141.6 | 108.6 | 39.639 | ||||
| m | m | m | m | 6.4 | 153.6 | 109.6 | 40.004 | |||
| m | m | m | m | m | 6.8 | 163.2 | 110.4 | 40.296 |
m = 100 Mbit, g = 1 Gbit
D-Link DGS-1005D
| Port # | 1 | 2 | 3 | 4 | 5 | Watt | 24h | 2h + 22h idle | kWh annually | |
|---|---|---|---|---|---|---|---|---|---|---|
| Adapter | 0.0 | 0.0 | 0.0 | 0.0 🙂 | ||||||
| 1.1 | 26.4 | 26.4 | 9.636 | |||||||
| g | 1.6 | 38.4 | 27.4 | 10.001 | ||||||
| g | m | 1.8 | 43.2 | 27.8 | 10.147 | |||||
| g | m | g | 2.1 | 50.4 | 28.4 | 10.366 | ||||
| g | m | g | g | 2.5 | 60 | 29.2 | 10.658 | |||
| g | m | g | g | g | 2.9 | 69.6 | 30 | 10.950 | ||
| g | m | m | g | g | 2.7 | 64.8 | 29.6 | 10.804 | ||
| g | m | m | m | g | 2.5 | 60 | 29.2 | 10.658 | ||
| g | m | m | m | m | 2.3 | 55.2 | 28.8 | 10.512 |
m = 100 Mbit, g = 1 Gbit
First of all it’s interesting to see that the power adapter from HP is using 1.4 watts on it’s own already. Besides that it’s nice to know that a 100Mbit port uses less energy than a Gigabit port. The Green Calculator is quiet right in my case. I’m saving about 72~74% of energy.