Greetings Phathak Sorry for the delay on reply. I used standard Tony Mac settings for this X79UD5 (thanks Tony Mac!). For X79 MainBoard I used below settings: 1- Set XHCI Handoff to Enabled 2- Set PCI ROM setting to 'legacy' For my (Nvidia 970 I had to do this). 3- Disable USB 3.0 4. If your CPU supports VT-d, disable it 5. Save and exit. (Optional) Set X.M.P. Memory Profile to Profile1 If you are are using latest Nvidia card then update PCI ROM setting to use 'legacy'. For my (Nvidia 970 I had to do this). For my Nvidia 560 I did not need to change this setting. Other than that I followed Tony Mac BIOS recommendations. There are a few post here about BIOS settings for gigabyte mainboards (Copy pasted a couple below). Message me if you get stuck. 1. To access BIOS/UEFI Setup, press and hold Delete on a USB Keyboard while the system is booting up 2. Set to Optimized Defaults. 3. (Optional) Set X.M.P. Memory Profile to Profile1 4. If your CPU supports VT-d, disable it 5. Save and exit. https://www.tonymacx86.com/threads/recommended-bios-uefi-settings-for-beginners.130920/ Also here: https://www.tonymacx86.com/threads/...upported-intel-based-pc.200564/#uefi_settings Recommended BIOS Settings If you're installing on a recommended CustoMac desktop with AMI UEFI BIOS, the options are simple. For other systems make sure to set your BIOS to Optimized Defaults, and your hard drive to AHCI mode. Here are standard AMI UEFI BIOS settings for Gigabyte AMI UEFI BIOS, Gigabyte AWARD BIOS, ASUS AMI UEFI BIOS, and MSI AMI UEFI BIOS. 1. To access BIOS/UEFI Setup, press and hold Delete on a USB Keyboard while the system is booting up 2. Load Optimized Defaults 3. If your CPU supports VT-d, disable it 4. If your system has CFG-Lock, disable it 5. If your system has Secure Boot Mode, disable it 6. Set OS Type to Other OS 7. If your system has IO SerialPort, disable it 8. Set XHCI Handoff to Enabled 9. If you have a 6 series or x58 system with AWARD BIOS, disable USB 3.0 10. Save and exit.