Is it normal that Win10 Pro x64 has 6 gigabytes of RAM instead of 8?

Question

Iron

Increased the RAM from two to eight. Is it normal that Win10 Pro x64 uses 6 gigabytes of RAM instead of 8?
1:

2:

3:
Processor:

4:
Video card: 512MB

I went into msconfig somehow set the maximum RAM and two processor cores, then only seven gigs were visible. Maybe all these RAM went somewhere for the full existence of the hard system?

Answer 1

Where is it written that 6 is used?
Busy/Free