martyn
Posts: 8
Joined: Sat Dec 24, 2011 3:41 pm

Does Pi use GPU if headless?

Sat Jul 04, 2015 2:42 pm

Hi everyone.

Apologies for the stupid question but I am planning on running motion on a headless Rev 2 Pi (I control it via SSH). Obviously I want to be able to squeeze as much memory use out of the CPU because it seems to struggle a bit with motion when the Pi camera has detected movement. It isn't anything mission critical - I want to use it to view what creatures are in the garden overnight.

Sooooo... should I wind down the GPU memory split to 16M or leave it at 128 etc?

Additionally - does anyone have any Pi specific tips that can help motion run at it's best on a Pi?

Any advice would be welcomed.

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rpdom
Posts: 16082
Joined: Sun May 06, 2012 5:17 am
Location: Chelmsford, Essex, UK

Re: Does Pi use GPU if headless?

Sat Jul 04, 2015 3:35 pm

The camera uses the GPU even if you have no screen connected. You won't be able to run the camera with a 16MB split. In fact I believe the 16M setting is ignored if the camera is enabled.

Leave it at 128M

mikerr
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Location: UK
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Re: Does Pi use GPU if headless?

Sat Jul 04, 2015 3:36 pm

Minimum GPU is 16meg.

The pi camera uses the GPU, so I think you might have trouble going less than 64meg.

Is this an A+ ? I run my A+ with motion/camera with 64M
- the A+ only has 256M total, so that extra CPU RAM makes a lot of difference.
Android app - Raspi Card Imager - download and image SD cards - No PC required !

martyn
Posts: 8
Joined: Sat Dec 24, 2011 3:41 pm

Re: Does Pi use GPU if headless?

Sat Jul 04, 2015 3:49 pm

Thanks for the advice gents.

I was trying to use the Model B Revision 1 board (one of the original ones first sold, with 256MB memory). I think trying to run motion on it in any useful way is beyond my capabilities, though I might try it again with the memory split as you have suggested.

Fortunately I have a couple of others I can run motion on, a Model B Revision 2 board with 512MB memory (with mounting holes) and if push comes to shove I will run it on a newer Pi 2 Model B (though I would prefer to keep this for other projects).

Thanks again for the suggestions.

mikerr
Posts: 2804
Joined: Thu Jan 12, 2012 12:46 pm
Location: UK
Contact: Website

Re: Does Pi use GPU if headless?

Sat Jul 04, 2015 4:23 pm

Here's a step by step for motion that I recently followed:

http://www.instructables.com/id/Raspber ... -software/

Initially I had my 256M A+ set on 128/128 and motion ran fine, but then moved to 192/64.

[edit] I've just had a play:

setting 16M GPU is ignored if the camera is enabled, and it resets itself back to 128M
32M is the lowest that still works with my motion setup.
if you want to use the display though, omxplayer needs 64M minimum.

Original 256M Pi (or A+) is more than enough for motion on its own IMO.
Android app - Raspi Card Imager - download and image SD cards - No PC required !

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