Is it normal for a Windows VM to use a lot of RAM even when idle?

[likecyber]

I just recently created a Windows VM in Proxmox VE.
I also installed QEMU Guest Agent and VirtIO Drivers on the Windows VM.
At first, it used minimal RAM like 2-4GB out of 32GB in Task Manager.
and it showed the same amount in the Proxmox VE dashboard.

And then I added the "SATA Controller" PCI Device to the Windows VM.
I noticed it takes much longer to boot up, from 30-40 seconds to like 3 minutes.
I understand that this would happen when adding a PCI device, it is okay.

After it boots up, it shows the RAM usage of 26GB out of 32GB (around 80%) in Task Manager.
It shows the same amount in the Proxmox VE dashboard as well.
It doesn't matter if I enable the Ballooing Device option or not, it results in the same.
The weird part is even though I removed the PCI device, this problem still persisted.

I have noticed that if I run any software for a while,
the memory usage will be decreased over time to the point of 3-6GB out of 32GB.

 

[BobhWasatch]

RAM must be pre-allocated when using PCI pass-through. This is because the device might do DMA to any address behind the back of the CPU.

Are you really sure you removed the device rather than just not using it?

 

[BobhWasatch]

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