Question How much free memory should a clean Windows 10 machine have in idle?

[farmhanddane]

No extra apps installed and so on.

 

[Zephyl]

How much memory a system "should" have is a bit subjective. I would argue that a budget system or a pre built these days should have at least 4GB of RAM open when at idle, assuming it has 8GB total. This may vary depending on many factors.

 

[punkncat]

This could vary significantly based on amount of memory and whether you have integrated graphics.
As far as "used" memory I typically see around 2GB being used, in idle with nothing but Windows defender running. On a machine I have with integrated graphics, it's using almost 3

On my actual "in use" machine with aftermarket AV and other utilities running around 4

 

[ex_bubblehead]

Asking "how much free memory should there be?" is just like asking "How high is up?" No two machines are alike.