Benchmark Results: PCMark Vantage
The productivity score is highest without system encryption, but BitLocker seems to benefit from Intel’s new AES-NI acceleration. Running on the dual-core Core i5-661, performance results are as high as on an unencrypted partition.
Performance in the Memories suite is higher on the quad-core Core i5-750. BitLocker appears to have a slight advantage on the dual-core again, likely due to the processor's AES-NI support.