I tryed iozone over NFS over GbE and I got about 90MB/s in the best reads.

Also did a

# time dd if=/dev/zero of=file4 bs=1024 count=10000000
10000000+0 records in
10000000+0 records out

real 2m45.938s
user 0m5.430s
sys 0m31.710s

which indicates over 100MB/s in over NFS

But I expected above 500MB/s from the disk and controller specs..