Areca 1.52 firmware has changed the bios architecture to be able to support multi-bios, so you have to update bios after updated the firmware to 1.52.

The update procedures will be

1. update raid card with 1.52 fimrware files except bios code.

2. reboot system once to activate new firmware

3. update raid card with the bios file.

4. reboot system once to activate the new bios code.