The system only recognize 3 Gb RAM

[Sheik]

Hi all.
I installed version 19.1.9 amd64 of OPNsense on an Intel Celeron 3205U at 1.5 Ghz (2 cores x64) with 4 Gb RAM
The problem is that OPNsense only recognizes 3 Gb of RAM despite having installed the 64-bit version.
How can I get the system to recognize all the installed RAM?
Thank you very much for your help.
Regards

[the-mk]

maybe your device has an onboard GPU that uses some of the RAM as Video-RAM?
how much RAM do you see i.e. in Windows for that device?