"The new Truecrypt 7.0 release is almost 7 times faster compared to 6.0 on my i7-620M with AES-NI. It is some hundred mb/s faster now than dmcrypt (which runs my system-encryption on Debian Squeeze), but that is expected since truecrypt makes use of multiple cores AND aes-ni and dmcrypt only supports 1 thread per mounted device, so unless you create a RAID consisting of multiple dmcrypt-devices, you can only use 1 core."
more:
http://www.robo47.net/blog/200-Truecrypt-7.0-Linux-AES-NI-Be...