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Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 5:40 am
by electronicsguy
Hello,
I just got my first raspberry pi B+ board and I love it. I tried searching the forum for this, but didn't find any relevant thread.
Can the RPi be kept always-on? Does anyone have any experience with this?

Is there any configurable standby/hibernate mode for the SoC/board? If so, can someone tell me where to find it?

Thank you.

Re: Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 7:51 am
by jimallyn
My Pi has been powered up continuously since I got it several months ago. I don't know anything about a standby mode, but that doesn't necessarily mean there is no such thing.

Re: Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 8:06 am
by shuckle
I have been running 3 raspis (model B) 24/7 for months. The longest is now over a year. No issues.
There is no standby/hibernate mode for Raspberry (it is hardly needed as it takes so littel power).

Re: Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 8:08 am
by ghans
The Linux versions for the Pi actually lack power-managment. The only thing they can do is adjust the CPU frequency dynamically
and turn a physically connected display black after some time (both can disabled or changed).

The GPU automatically powers down unused parts. AFAIK we have no control over that.

People have had the Pi running continously for months or years. It's a Linux box , it's supposed to work that way :lol:

ghans

Re: Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 4:05 pm
by DougieLawson
shuckle wrote:I have been running 3 raspis (model B) 24/7 for months. The longest is now over a year. No issues.
There is no standby/hibernate mode for Raspberry (it is hardly needed as it takes so littel power).
I'm running one A+, one RPI2 and five Bs. They each cost less than £1 per year to run so they stay on 24x365.

Re: Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 4:08 pm
by Joe Schmoe
I'm guessing that the issue isn't stability (or, more generally, will anything bad happen if I leave it on all the time?), but rather one of power usage.

And the usual answer to that is: It uses so little power that it doesn't matter.

(Unless electricity is really expensive where you are…)

Re: Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 4:09 pm
by RaTTuS
yes to the OP
no problem in just keeping it running forever*
it does not use a lot of power - probably less than most other things in your house



[*forever may not be for ever]

Re: Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 7:02 pm
by gcsx
Actually, the Pis are able to do something like a standby mode, but you need an external trigger to restart it.

If you shutdown your Pi with, for example,

Code: Select all

sudo poweroff
, your Pi's will shut down properly and the SOC will go to sleep.

In this state, you can reset your Pi by triggering the RUN pads.
Doing so is exactly the same as unplugging and plugging back the power.
You can do it by soldering a connector, a button or anything else with a normally open switch.

Here is an example for a RESET button : http://blog.adafruit.com/2014/10/10/mak ... pberry_pi/

Re: Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 7:12 pm
by ghans
Note that this approach technically and practically
equals a simple reboot of the Pi.

ghans

Re: Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 7:25 pm
by mikerr
It's not an issue on mains power, as the Pi's 2W usage is probably less than standby consumption of many other devices.

Re: Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 7:27 pm
by electronicsguy
Thanks everyone for your answers. I guess I could just leave it on. I am surprised that a timed-standby is not supported, since I assumed that would be part of this linux kernel, just like any other linux kernel.

A follow-up: I bought the Pi tru the Canakit, and it came with a heatsink. They say its not required. Have any of you come across a overheating situation, esp. with always-on scenarios? When you say you never faced a problem, was it with the heatsink (or some other cooling) or without it?

best regards,

Re: Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 7:42 pm
by rpdom
The only heatsink I've used on a Pi is on my very-early model B with the 1V8 wiring fault (1V8 output from the LAN9512 chip connected to output from 1V8 Vreg). The LAN9512 gets pretty hot because of that, so I put a spare heatsink on it just in case.

I've never put a heatsink on any of the BCM chips.

If you're worried, check the temperature...

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rpdom@raspi:~$ vcgencmd measure_temp
temp=48.7'C
If it starts getting close to 85 degrees you might have some benefit from a heatsink to prevent the CPU slowing down.

Re: Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 10:29 pm
by jimallyn
I got my RPi from Canakit, too. Didn't use the heat sink.

Re: Can the RPi be kept always-on? any standby mode?

Posted: Thu Feb 12, 2015 10:49 pm
by jbeale
I've had a few Pi's run for about a year, one of them longer:

Code: Select all

uptime:  14:39:19 up 452 days, 22:29,  1 user,  load average: 1.10, 1.08, 1.10
that one is in a server rack with controlled environment but I have another one outdoors, sometimes in direct sun (inside a case) doing motion detection and streaming video 24/7. I log the internal CPU temperature and it ranges from 32 C (winter morning) to 58 C (summer afternoon). There is no heatsink and I have never had an issue related to that. (Admittedly this is the SF Bay area, not the north pole or a desert.) One time I had some rain get into an ethernet cable joint that wasn't well waterproofed, but that's not the Pi's fault.