Full Disk Encryption vs Encrypt whats in use

Hello kire,

"Encrypt whats in use" which took about 4 hours

it's called Fast Initial Encryption for a reason. The time needed for encrypting a disk is roughly directly proportional to its size. Thus on a 500GB disk with a freshly installed Windows 7 or 8.1 (about 20GB) FIE will save you more than 90% of time for initial encryption (4 hours suggests that there's more than the OS on your test PC).

if the disk continues to encrypt as it grows or not?

While FIE encrypts only allocated (i.e. in use) sectors all new data written will be encrypted whether the sector was previously allocated (and therefore encrypted) or not.

why have to two different options?

As mentioned above, FIE takes considerably less time. It is only "safe" though on volumes which do not yet contain any sensitive data at all (ideally just the OS) as the unallocated sectors likely contain previously deleted but unencrypted data. 

Christian  

Thanks for the reply.  Good information there.

Yeah my test PC had several programs from my company as well as it was PC that someone used for a period of time before switching over to a laptop.

Im not worried about the speed honestly.  I know there are several factors involved there.  I was mainly concerned about the difference between the two types of encryption.  

So based on my environment and how I am going to use the product it sounds like full disk encryption is what I need.  The laptops that are going to receive this encryption have been in use for a while so data on them has "come and gone" so to speak.  Potentially leaving behind information on what is now unused sectors of the Hard Drive. 

Im glad I raised this question because I was simply going to stick with FIE method, but now I think I will go Full Disk.

Thanks a million.

Also my laptop encrypted using the FIE method.   I just changed in the policy that FIE is set to "No".  I expected to see it update its policy (it did), and then expected to see that encryption box pop up letting me know it was encrypting the rest of the Hard Drive (it did not).  Will I have to uninstall and re-encrypt or is there a way to verify its doing the rest of the drive now?