SH wrote

The solution to all of this is full disc encryption. Without the
password the disc is full of random noise.

Yes, Windows comes with Bitlocker. I am curious to know what the CPU
overhead is for decrypting on the fly the encrypted data on said drive?

Not enough to matter with the stuff you
dont want anyone else to be able to see.

If you are concerned about the disc falling into the wrong hands (on a
laptop, or at disposal time) then FDE will protect against that.

Is Bitlocker considered to be a FDE?

SSDs typically do FDE 'for free' - the raw flash
is encrypted, and a 'secure erase' is simply deleting the key from inside
the controller.

Thats interesting to know, why is FDE used on SSDs? I don't see it
advertised as a feature on the advertising blurb so it gives one the
impression that one needs to deploy FDE....

You dont see it advertised with laptops either but very few dont have it.

Deleting the key is not the same thing as securely erasing the key with an
overwrite so my question is can the "deleted" key be recovered?

It isnt anything stored anywhere.

Also SSD's use wear levelling so an overwrite may end up on a physically
different location on the flash NAND chips?

Not if you overwrite everything.

No angle grinders needed.