Hello, do you have any suggestion ? :     B120i controller is set in SATA AHCI mode in BIOS.   $ sudo dd bs=1M count=4096 if=/dev/zero of=/volume1/testx conv=fdatasync 4096+0 records in 4096+0 records out 4294967296 bytes (4.3 GB) copied, 14.442 s, 297 MB/s   $ dd if=/dev/zero bs=1M count=4096 | md5sum 4096+0 records in 4096+0 records out 4294967296 bytes (4.3 GB) copied, 10.7008 s, 401 MB/s c9a5a6878d97b48cc965c1e41859f034  - orphee@NAS-G