I've got 4 RE4's of the same size, speed, and interface on that very same controller and using the test you suggested I get this:
4294967296 bytes (4.3 GB) copied, 31.474 s, 136 MB/s
A more common test used among this crowd is: dd if=/dev/zero of=test bs=64k count=16k conv=fdatasync
To which...