available System memory

[kamalbd26]

MB: gigabyte GA-B85M-hd3
Processor: Pentium(R) G3220 (4th Gen)
Ram: 8 GB (Goldkey) + 4 GB transend

Install total physical memory is 12 gb
but total available physical memory is 6.60 gb

Why?

 

[SkyNetRising]

Don't know.
Could be hardware issue, could be software issue.

You have to specify your pc hardware specs to receive any better answer.
Screenshots illustrating the problem also would be good:
cpu-z memory and spd sections, resource monitor memory section.