The OpenSSL test doesn't use the disk that much, but in case you were wondering, the RSA 4096-bit performance was virtually identical with less than a second difference separating all four file-systems.
Our 19th and final test was with the Java-powered Bork File Encrypter. Bork is a lightweight, cross-platform encryption utility. With the Phoronix Test Suite we were using a 2GB reference file. The fastest performance here was found with the EXT4 file-system. EXT3 had a respectable second place finish followed by XFS and ReiserFS.