Take the 2-minute tour ×
Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems.. It's 100% free, no registration required.

During the installation of Lubuntu I chose to encrypt my whole HDD (not just the /home folder). Now it feels like my system has slowed down a lot. Especially the startup time of programs increased.

Does this encryption also slow down programs (after loading) which neither read from nor write to the HDD?

share|improve this question
add comment

1 Answer

It depends on a few things. Encrypting a disk CAN make it slower. For example, if you have an SSD capable of 500mb/sec and then do full disk encryption on it using some crazy long algorithm you might get FAR below that max of 500mb/sec. I've attached a quick benchmark from TrueCrypt.

There is CPU/Memory overhead for any encryption scheme.

enter image description here

You can see if I just used AES things are going to be pretty fast... but Serpent-Twofish-AES is many factors slower.

share|improve this answer
    
My harddrive is slower than my CPU using most of encryption algorithms. But my question was aimed at harddrive independent programs. Is the RAM encrypted too? –  Stein Apr 20 '13 at 20:22
1  
@Stein No, the RAM isn't encrypted. Encrypting the disk ties up the CPU for disk I/O (not much on recent CPUs), but doesn't otherwise slow the execution of programs when they are fully running off RAM. –  Gilles Apr 20 '13 at 23:49
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.