VeraCrypt is a free disk encryption software, that is based on TrueCrypt 7.1a.

If you are suffering slow boot up with VeraCrypt, you password takes ages to be accepted or slow pre boot authentication then read on…

When I first tested VeraCrypt with Windows 10, I had problems with it taking around a minute to process the password in the pre-boot environment. After a couple of boots, I wondered if this was really a workable potion at this time.

I then found this was due to the “Personal Iterations Multiplier”, PIM. It is a parameter that was introduced in VeraCrypt 1.12 and whose value controls the number of iterations used by the header key derivation function.

As shown in the screenshots, it is possible to set this value as you wish, some quick tests showed setting the value to 1 took less than a second. Therefore, I recommend reviewing the documentation and then selecting an appropriate value if you are suffering from this problem.

https://veracrypt.codeplex.com/wikipage?title=Personal%20Iterations%20Multiplier%20%28PIM%29