Intel Thunderbolt Support in Windows

Intel supports Thunderbolt, Thunderbolt 2, and Thunderbolt 3 controllers under Windows 7, 8, 8.1, and Windows 10 Operating Systems through a combination of the Intel Thunderbolt software/firmware as well as the Intel Thunderbolt Reference BIOS (BIOS Assisted Mode).

 

Hardware differences:

• First-generation Thunderbolt and Thunderbolt 2 devices use  Mini DisplayPort (mDP) connectors.
• Thunderbolt 3 devices use USB Type-C connectors.

 

Software differences:

Starting with Windows 10 Redstone 2 (version 1703), Microsoft has included 'Native PCI Express support for Thunderbolt Controllers.' Native Express mode provides:

• Dynamic resource allocation for Thunderbolt bridges. This replaces the current BIOS functionality and allows Thunderbolt controllers to take advantage of the lowest power states available to achieve Modern Standby for systems.
• Native Microsoft support for Thunderbolt 3 systems and peripherals.
• Ability to use Microsoft’s inbox drivers (USB, SATA and NVMe storage over Thunderbolt).
• OS support infrastructure.

Prior to Windows 10 Redstone 2 (version 1703), Microsoft provided support through 'BIOS Assisted Mode.' BIOS Assisted Mode support provides:

• Basic configuration of the Thunderbolt controller to support Thunderbolt devices.
• Workarounds for hardware-limiting issues that are addressable through BIOS configuration changes.

Support Changes:

For platforms that are designed to support Native Express mode, Intel is changing the official Thunderbolt and Thunderbolt 2 support policy for the following configurations due to known OS and chipset limitations. Beginning with Windows 10 Redstone 3 (version 1709), the following configuration restrictions apply:

1. Devices based on the Intel CV82524EF Thunderbolt Controller or Intel CV82524EFL Thunderbolt Controller will not be supported when the platform is in Native Express mode. This is due to the fact that these first-generation devices are not capable of waking from OS sleep states due to chipset limitations and would become unavailable after the system resumes from the sleep state.
2. No more than 2 devices should be 'daisy-chained' with systems with Intel Thunderbolt and Intel Thunderbolt 2 controllers (CV82524EF or CV82524EFL do not support daisy-chaining). This ensures that the OS does not run out of PCI / Memory resources to assign to devices.

No cause associated

Questions and Answers

Q: How does Thunderbolt use BIOS Assisted Mode?
A: In the BIOS Assisted Mode, the BIOS pre-allocates resources including PCIe and Memory resources for use by the OS in order handle adding and removing Thunderbolt devices. This ensures that devices that are added and removed would not negatively impact the system performance or user experience. 

Q: What is Native PCIe Express support for Thunderbolt Controllers?
A: Starting with Microsoft Windows 10 version 1709 (Redstone 3), Microsoft has taken the steps to improve user experience by pre-allocating PCIe and Memory resources for Thunderbolt 3 devices to significantly improve the user experience. This enables Microsoft’s inbox drivers (USB, SATA and NVMe storage) to operate over a Thunderbolt interface without the need for additional 3rd party drivers.

Q: What is the benefit to Native Express mode over the previous BIOS Assisted Mode?
A: The biggest benefit to end users is the ability to use Microsoft’s inbox drivers and OS support infrastructure to improve performance.

Q: Does this impact all Thunderbolt 3 systems?
A: No. Dell platforms that shipped originally with Windows 10 Redstone 2 or earlier only support the BIOS Assisted Mode.

Q: Can I upgrade my computer to support Native Express Mode?
A: Devices based on the Intel CV82524EF Thunderbolt controller or Intel CV82524EFL Thunderbolt controller will not be supported when the platform is in Native Express mode.

Q: Does Microsoft support Thunderbolt and Thunderbolt 2 devices with Native PCIe Enumeration?
A: No. Microsoft only supports Thunderbolt 3 devices on systems with Native Express mode enabled. Thunderbolt and Thunderbolt 2 devices are supported under BIOS Assisted Mode.

Q: If I have a system that does not include support for Native Express mode, who will support my devices?
A: The device should work fine in BIOS Assisted Mode without any issues. If you see any issues, please work with your Thunderbolt, Thunderbolt 2, and Thunderbolt 3 device vendor directly for support.