UnderClocking CPU

[Josweet]

Would it be possible to add an "Underclocking" CPU feature to a future merlin build.
Im running an RT AX88U F/w & even with multiple device connected (Wifi & hardwired) + a USb media server, my CPU usage never reaches about 10%, so by reducing the CPU clock i could lower the units temperature and electric consumption.
Currently here in the UK, the router alone will cost approx £120 per year to run, which would be nice to try and lower that in some way.

 

[RMerlin]

Would it be possible to add an "Underclocking" CPU feature to a future merlin build.

The CPU clock cannot be adjusted.

 

[BreakingDad]

You could use the wireless scheduler to turn off wifi at night, that will save you a few watts if you don't have devices that need wifi all night. You could also turn down the transmit power to save a few more watts, assuming you don't need full range. Also you can set attached SSD's to powerdown after being not used for a while.

OC/UC is a risky business unless you really know what you're doing, you could end up bricking the router or at least damaging it.

 

[ColinTaylor]

Currently here in the UK, the router alone will cost approx £120 per year to run, which would be nice to try and lower that in some way.

There was recently a similar discussion in another thread. In that thread I measured the power consumption of my RT-AX86U in normal operation and found it consumed 9.0 Watts. So that's 78.84 kWh a year. EDF's current variable tariff is 35.32p per kWh which would equate to a total cost of £27.85 a year.

 

[sfx2000]

Can't speak for Broadcom, but in my experience with other SoC vendors, the ARM cores, even older ones like Cortex-A9, are very efficient, even at max clock speeds on chips that implement dynamic frequency and voltages... so dropping from let's say 1.6GHz to 800Mhz, it's hardly noticeable.

It's the other things inside the SoC that consume power - the switch, the PCI/PCI-e busses, USB, RAM/flash busses...

 

[heysoundude]

It's the other things inside the SoC that consume power - the switch, the PCI/PCI-e busses, USB, RAM/flash busses...

Good point - and it reminds me of discussions in a thread about router temperatures a while back: routers don't have to dissipate heat that they don't consume. people were shutting off LEDs with the scheduler to prevent heat build-up (hoping to prolong service lives and/or prevent premature failure/throttling), and/or moving to using to external switches to avoid the lights on the router illuminating (but those consume their own power from a different supply, which doesn't help in this case). Between @BreakingDad 's suggestion to schedule the radios off when they're not being used and mine to shut off the lights, OP can probably lower the costs of running the router a few quid below @ColinTaylor 's calculation...maybe even enough savings to afford a celebratory pint by the end of a year.

 

[Martinski]

Good point - and it reminds me of discussions in a thread about router temperatures a while back: routers don't have to dissipate heat that they don't consume.

"... routers don't have to dissipate heat that they don't consume generate."

 

[sfx2000]

Between @BreakingDad 's suggestion to schedule the radios off when they're not being used and mine to shut off the lights, OP can probably lower the costs of running the router a few quid below @ColinTaylor 's calculation...maybe even enough savings to afford a celebratory pint by the end of a year.

Scheduling or disabling the radios is probably the best approach. - current WiFi5 and WiFi6/6e wireless chipsets probably have just as much of a power impact as the main SoC, and there is the RF front end (LNA on the receive and PA on the transmit) - so bringing them down should reduce power consumption and heat...

 

[ColinTaylor]

Scheduling or disabling the radios is probably the best approach. - current WiFi5 and WiFi6/6e wireless chipsets probably have just as much of a power impact as the main SoC, and there is the RF front end (LNA on the receive and PA on the transmit) - so bringing them down should reduce power consumption and heat...

As I mentioned in the other thread disabling both radios on my RT-AX86U reduced the power consumption from 9.0W to 6.2W. So based on the costs in post #4 that would be a saving of £8.66 a year - but then you'd have no WiFi at all. So just enough for two pints and a packet of crisps.

 

[sfx2000]

As I mentioned in the other thread disabling both radios on my RT-AX86U reduced the power consumption from 9.0W to 6.2W. So based on the costs in post #4 that would be a saving of £8.66 a year - but then you'd have no WiFi at all. So just enough for two pints and a packet of crisps.

WiFi scheduler?

there's most of the night, early morning where things could be turned off perhaps...

 

[ColinTaylor]

WiFi scheduler?

there's most of the night, early morning where things could be turned off perhaps...

In case it wasn't obvious I was trying to point out that any potential savings, in power and money, would be negligible.

 

[sfx2000]

In case it wasn't obvious I was trying to point out that any potential savings, in power and money, would be negligible

power on the broadband modem is also a concern - most CM/DSL modems are not engineering for minimizing power consumption...

 

[Sumsurfguy]

power on the broadband modem is also a concern - most CM/DSL modems are not engineering for minimizing power consumption...

Even if you have a modem that can reduce power consumption it might not do any good, my arris has energy efficient ethernet and it can be enabled, but a few seconds later its automatically disabled, which im assuming is a product of the isp firmware, why they'd do that I have no idea, but it worked before an update a couple of years ago.