8G SOM only show 6.7G memory size on JP5.02

Hi

We test found Xavier NX 8G SOM on JP5.02, only 6.7G memory is avaiable. Could you please elaborate Xavier NX memory usage or reserverd? Thanks.

lenovo@lenovo-desktop:~$ cat /etc/nv_tegra_release

R35 (release), REVISION: 1.0, GCID: 31250864, BOARD: t186ref, EABI: aarch64, DATE: Thu Aug 11 03:40:29 UTC 2022

lenovo@lenovo-desktop:~$ free -h
total used free shared buff/cache available
Mem: 6.7Gi 1.8Gi 3.6Gi 15Mi 1.3Gi 4.7Gi
Swap: 3.3Gi 0B 3.3Gi

Hi,
It looks to be necessary for K5.10 and Ubuntu 20.04. Not sure if you need Ubuntu desktop in your use-case. If it is not a must-have, please try to generate minimum rootfs and see it it meets your requirement. Please take a look at
Root File System — Jetson Linux
Developer Guide 34.1 documentation (nvidia.com)

Hi Kayccc

Additional info:
What I mentioned is memory, 8G SOM memory should be about 8G avaiable by ‘free’ command.
the same SOM on JP4.6.2 (Kernel 4.9 and ubuntu 18.04) show memory size is about 7.9G.

However, when run it on JP5.02 (Kernel 5.10 and ubuntu 20.04), which show about 6.7G. Big change, right?

Hi,
Please check
Memory loss when flash L4T 35.1

If Ubuntu 20.04 and K5.10 are not hard requirement in you ruse-case, please use Jetpack 4 release.