I've not used TrueCrypt before, but I just rolled out a product called GuardianEdge and have messed around with BitLocker a little. Neither had much of a performance impact, aside from a little longer ...
Tom's Hardware has found that the default software-based BitLocker encryption (XTS-AES 128, where XTX stands for XEX Tweakable Block Cipher with Ciphertext Stealing and AES is Advanced Encryption ...