Motherboards may lack sufficient resources to support a large number of bootable devices. This is related to INT13 supporting a certain number of devices (24). After all INT13 devices have been utilized, the motherboard no longer has sufficient option ROM to support additional bootable devices. This may result in:

• Drives not being passed through to the operating system (OS)
• Controllers not completing POST
• Inability to boot to the OS

Suitable workarounds include:

• Disabling all unused onboard devices
• Disable BIOS of all controllers/HBAs which are not being used as boot devices

MegaRAID controllers allow you to disable INT13 device registration. This can be accomplished by disabling the BIOS in the Controller Properties menu of the WebBIOS.

SAS HBA products allow you to adjust the total number of INT13 devices passed through to the motherboard BIOS. This can be accomplished by changing the the Maximum INT 13 Devices for this Adapter value in the Advanced Device Properties menu of the Configuration Utility