dolson14
Posts: 21
Joined: Sat May 12, 2012 12:20 am
Contact: Website

Re: Double Check RAM Quantity

Sat May 12, 2012 1:36 am

I just receive my Raspberry Pi today! All has gone very well; I was able to install Arch on my SD card (Kingston SDHC 8GB), expand the partition etc., and boot everything up. (In Arch, I did need to remove /boot/config.txt to get the HDMI to display to my DVI monitor.)

I installed xorg with xfce4, which after a bit of a wait does open up and works quite well. I wanted to see how much of the RAM was being used by xfce (and whether I'd rather go to a different, unfamiliar session), and found something a little perplexing in the output of top:



Note the Mem: line– it lists the total memory available as 125004 kB, not the 256 MB I was expecting… is this normal? If so, where is the other half of the RAM?

shirro
Posts: 248
Joined: Tue Jan 24, 2012 4:54 am

Re: Double Check RAM Quantity

Sat May 12, 2012 2:16 am

The GPU has the other 128MB reserved for itself.

If you don't think it needs that much you can

sudo cp /boot/arm192_start.elf /boot/start.elf

to get 192MB or

sudo cp /boot/arm224_start.elf /boot/start.elf

to get 224MB.

Reboot for the change to take effect. The different memory splits are good for different purposes. If you don't wish to play video or use 3D graphics then 224 will be best. If you aren't doing hd video and not much 3d then 192. For a media centre or 3d games your would want the 128/128 split.


dolson14
Posts: 21
Joined: Sat May 12, 2012 12:20 am
Contact: Website

Re: Double Check RAM Quantity

Sat May 12, 2012 3:03 am

Got it; thanks.

Jancis
Posts: 25
Joined: Thu Jan 26, 2012 3:54 pm

Re: Double Check RAM Quantity

Sat May 12, 2012 3:20 pm

shirro said:


The GPU has the other 128MB reserved for itself.

If you don't think it needs that much you can

sudo cp /boot/arm192_start.elf /boot/start.elf

to get 192MB or

sudo cp /boot/arm224_start.elf /boot/start.elf

to get 224MB.

Reboot for the change to take effect. The different memory splits are good for different purposes. If you don't wish to play video or use 3D graphics then 224 will be best. If you aren't doing hd video and not much 3d then 192. For a media centre or 3d games your would want the 128/128 split.


This is one of those info pieces we should bookmark and keep documented. Thanks Shirro!

Return to “Troubleshooting”