SCSI Controller BIOS Extension Reports 80MB/s


When booting a SBC with a SCSI controller an error message:
"This device has been validated to run at 80MB/s and should support 320MB/s when the operating system is loaded".


This is not an error message but rather a result of the limitation imposed on the SCSI controller chip's BIOS extension by x86 BIOS. Due to the limited memory space reserved by x86 BIOS for BIOS extensions during the boot process, most SCSI controller vendors decided not to load support (BIOS drivers/services) for U160 or U320 devices at boot time, especially when using embedded multi-controllers. Once the U160/U320 SCSI driver loads in the operating system the devices renegotiate (domain validation is re-initiated) and support for the fastest domain-validated speed is loaded and used from this point on.