Hello beshkenadze,
Were you installing the latest version for ESXi are you installing?
Did you try both Intel and ASMedia SATA ports on your MB?
Have you updated your BIOS to the latest version available from ASUS web-site?
Also, try changing SATA Mode Selection in the BIOS.
The reason why I think it should work is that while I have the main datastore with RAID 10, my boot drive with ESXi is
smaller laptop SATA drive.
Let me know how it works out.