Intel’s newest chips include a new AES hardware acceleration feature. My favorite cross-platform encryption utility, TrueCrypt, recently added support for the new instructions (Turn it on in Setting->Performance in Windows or Settings->Preferences->Performance in Linux).
However, I noticed something interesting when comparing the benchmark performance in Windows 7 to that in Linux. It seems that Linux is significantly faster than Windows, even though the acceleration is hardware-based.
Each data point represents the average of three (3) runs. The operating systems used were Windows 7 Professional 64-bit, Arch Linux 64-bit (latest) and Ubuntu 10.10 64-bit. Tests were performed on a ThinkPad T510 with an Intel Core i5 M 560 processor and 4 GB of memory.
|Block Size||Windows 7||Arch Linux||Ubuntu|
|1 MB||377 MB/s||1.5 GB/s||1.5 GB/s|
|5 MB||798 MB/s||1.6 GB/s||1.6 GB/s|
|50 MB||1.1 GB/s||1.7 GB/s||1.6 GB/s|
|200 MB||1.3 GB/s||1.6 GB/s||1.7 GB/s|
Bottom line: If you plan to do a lot of encryption, Linux will give you noticeably better performance, assuming all your data is already in memory.