Why Only 3.85GB Ram usable from 4GB?

[Aladdad]

I have a laptop, and have 4 GB of ram installed.. but only 3.85 Usable.. never had such thing.. my other laptop have 8GB and its fully usable while my desktop has 16GB and its fully usable? why does such thing happen?
Specs: i5 2410m 2.30Ghz
4GB ram
Windows 10 home 64Bit
Nvidia GT520m
it is an Acer laptop

 

[Guest]

I have a laptop, and have 4 GB of ram installed.. but only 3.85 Usable.. never had such thing.. my other laptop have 8GB and its fully usable while my desktop has 16GB and its fully usable? why does such thing happen?
Specs: i5 2410m 2.30Ghz
4GB ram
Windows 10 home 64Bit
Nvidia GT520m
it is an Acer laptop

The gpu needs it

 

[neieus]

As stated above part of your memory is being used by your laptops GPU which is normal.

 

[Aladdad]

I have a laptop, and have 4 GB of ram installed.. but only 3.85 Usable.. never had such thing.. my other laptop have 8GB and its fully usable while my desktop has 16GB and its fully usable? why does such thing happen?
Specs: i5 2410m 2.30Ghz
4GB ram
Windows 10 home 64Bit
Nvidia GT520m
it is an Acer laptop

The gpu needs it

Oh? i thought dedicated GPU's did not require memory from ram. Okay thanks!

 

[neieus]

It has taken me some time to find this but here are some specifics related to the memory... keep in mind this could vary by manufacture.

NVIDIA® GeForce® GT 520M with NVIDIA® Optimus™ technology, up to 40956 MB of TurboCache™ (512 MB of dedicated DDR3 VRAM, up to 35833 MB of shared system memory), supporting NVIDIA® CUDA™, PhysX™, PureVideo® HD technology, OpenEXR High Dynamic-Range (HDR) technology, Shader Model 5.0, Microsoft® DirectX® 11

It's possible that your previous laptop GPU had more allocated memory but it's pretty normal for laptops to share memory with your system. The simple solution would be to add additional memory to your laptop and IMO you should at least bump it up to 8GB just so that you have some overhead memory space.