Rock Pi N10 model C only show 3GB for CPU memory

Recently bought a Rock Pi N10 model C and expected to see 4GB memory for CPU and 4GB memory for NPU, but when I run “free -m” or “top” and all show only has 2.99GB (3GB) total memory. Does any one encounter the same issue? How to fix it? By the way is there a cmd to check NPU memory size?

I installed debian buster for my unit on a microSD card. Am I missing something? Please help.

Thank you.

Mine looks right (4GB)

rock@rockpin10:~$ cat /etc/os-release
VERSION=“18.04 LTS (Bionic Beaver)”
PRETTY_NAME=“Ubuntu 18.04 LTS”

rock@rockpin10:~$ free -m
total used free shared buff/cache available
Mem: 3808 66 1965 32 1776 3680
Swap: 0 0 0
rock@rockpin10:~$ uname -a
Linux rockpin10 4.4.167-8-rockchip-g1175e66f8e9a #1 SMP Thu Mar 5 08:40:28 UTC 2020 aarch64 aarch64 aarch64 GNU/Linux

Note the cma-reserved/reserved:

[ 0.000000] Memory: 3630808K/4061184K available (13054K kernel code, 1586K rwdata, 4580K rodata, 1152K init, 2107K bss, 168232K reserved, 262144K cma-reserved)


Thank you for your information.

My installation is:
PRETTY_NAME=“Debian GNU/Linux 10 (buster)”
NAME=“Debian GNU/Linux”
VERSION=“10 (buster)”


  1. do you think because of debian limited to 3GB? (very unlikely, right?)
  2. when I type “uname -a”, the cma-reserved info did not show up and only show up:

rock@rockpin10bc:~/rk3399pro$ uname -a
Linux rockpin10bc 4.4.167-14-rockchip-g53bdb2fa44e8 #1 SMP Fri May 22 09:11:08 UTC 2020 aarch64 GNU/Linux

What cmd should I type to see the NPU memory? or which file I should cat to see the cma-reserved info?

  1. where did you install your OS: microSD card? or eMMC? (would this matter?)

Thanks a lot for your help.

For the cma - run the following: dmesg | grew cma
Maybe also dmesg | pastebinit and share the url.

I would think Debian would support the whole 4GB. Is your N10 a B series maybe?

I did the sd card boot first, and then replaced the eMMC image with the downloaded file from using dd if=xxxx of=/dev/mmcXXX

I think you bought from allnet which advertised 5 GB RAM.

Seeedstudio said it only 3GB for CPU RAM and 1 GB for NPU RAM


after I flash debian buster into eMMC and remove microSD card, when bootup the system reports 4GB memory for CPU and 4GB memory for GPU.

I think the reason previously only show 3GB for CPU and 3GB for NPU is because the manufacturing preinstalled ToyRock in eMMC reserved 1GB for CPU and 1GB for NPU thus when bootup from SD card, the system can only see the balance.

So mystery solved.

1 Like

Thanks for the details!

NOTE: For model A+, please use the firmware of model B&C. Model A firmware(3GB CPU ram) is different from the other three models.

All the Model A produced after Dec, 2020 are actually A+ version with 4GB ram for CPU and 1GB ram for NPU.

Just added it to the wiki: