I have 4 gb ram but just shows 3,7 GiB of RAM?

[ardv]

why Ii have 4 gb ram while manjaro just shows 3,7 GiB of RAM?

[Jtyle6]

I think that you have a integrated graphics card.

Please post information about your system.

[HowTo] Provide System Information

This tutorial is superseded by this one. Remember all Tutorials are wiki posts that can be edited by TL2 (Trust Level 2) members and above. Welcome to Manjaro! To allow all of us helpful people on this forum TO HELP YOU, we need some basic information about your system. This probably means you described the symptoms of your problem, but now we need some more information to know where the origin of your issue is exactly. Someone else probably linked you to…

[cscs]

Besides system-reserved memory I’ll also get out ahead and mention the ‘GiB’.
Please recognize there are differences in Gigabyte, Gibibyte, etc.

GB to GiB Conversion Gigabyte to Gibibyte Calculator

4 GB = 3.725290298 GiB

[Aragorn]

Part of the address space between 3 GiB and the 4 GiB boundary is reserved for legacy hardware, such as PCI devices. Those are 32-bit devices and they cannot access any memory above the 4 GiB barrier.

Therefore, an address range is reserved for them right underneath the 4 GiB barrier, extending downward, depending on how many legacy PCI devices you still have.