I've been away from OpenWRT for a while, so I'm kind of out of the loop as far as modern hardware goes, but I have a project coming up where I need a lightweight router with the primary requirement that it needs to be somewhat power-efficient. The device will typically be powered by mains, but it will be attached to a battery-backup unit in the event of a power outage, and I'd like it to be able to survive as long as possible while on battery.
I don't need wifi, but it's not a deal-breaker if the device includes it. It doesn't have to be very performant, as it will be behind a fairly terrible DSL connection.
My long-time go-to for OpenWRT has been the TP-Link Archer C7 AC1900 series, but those devices are getting fairly old, so I was curious if anyone had any suggestions.
Some of the Atheros SoCs are quite low power. For example I have measured a TP-Link WA-701ND (AR 9344 chip I think) stock hardware running a release OpenWrt at 60 mA at 12 volts, which is less than 1 watt.
Avoid gigabit Ethernet and 5 GHz wireless, chips that do these tend to need considerably more energy than 10/100 and 2.4. Also the concept of the OS being able to completely shut down an unused subsystem to save power is rarely supported.
Sorry for the late replies, work has been trying to kill me these last few weeks.
Maybe I overstated the low-power part. It will be attached to a normal 1500 VA UPS with 120 VAC output, so it doesn't need to be a specialty unit or anything like that, I'm just aiming for a long survival time when it's on battery. It will be sharing the battery backup with a 15w Intel NUC, which I'm sure won't consume anywhere near 15w when it's idle, so it's not extremely critical, I just didn't want something with a really high power SoC wasting power/battery time when it will be attached to an ancient ADSL line with minimal throughput.
It does need at least 1 WAN and 1 LAN port, but I would prefer the typical 1 WAN/4 LAN.
I guess what I really wanted to ask was for more up-to-date hardware suggestions than the Archer C7/C9 units I used to buy years ago, leaning towards lower-end units instead of something with like a 2 GHz SoC.
I've been pretty happy with my EdgeRouter X (MT7621 dual core MIPS at 880 MHz) running a recent OpenWrt snapshot. No WiFi. Router only. It has the typical 4/1 port setup in a very small metal case no wider than the ports.
The Edgerouter X is rated at 5W Max, as compared to just under ~5W average for an Archer C7. I chose my Edgerouter X specifically for the performance/power ratio, as it is stuffed into roughly a 12 inch square metal telecom junction box between 2x4 wall studs, and I didn't want anything getting too hot inside the walls of the house. It runs pretty cool, so I doubt it's drawing a lot of power on average, but I've not measured it. It will handle ~185Mbps CAKE SQM QoS, which you will definitely appreciate with DSL service