More Thunderbolt on Windows compatibility lessons for Mac owners

The compatibility picture with Thunderbolt on Macs running Windows is complicated and will continue to be so, according to one storage engineer.
Written by David Morgenstern, Contributor

Mac users have enjoyed the use of high-performance Thunderbolt devices for several years even when running Windows. However, customers have complained that the Thunderbolt experience and compatibility with Windows isn't seamless. According to a storage engineer in the know, that situation will continue.

Mac owners have had the advantage of running Thunderbolt on their Macs since early 2011, with its introduction on the MacBook Pro line and soon thereafter across the Mac lines. The long-awaited, forthcoming Mac Pro will include a Thunderbolt 2 interface. Until the middle of last year, the majority of Windows users connecting to a Thunderbolt display or storage device were Mac users running Windows.

However, many find the compatibility situation complicated, as I wrote recently in Boot Camp Windows presents some limitations with Thunderbolt.

While Windows currently doesn't support Thunderbolt, a number of vendors provide Windows-specific drivers for their Thunderbolt devices. At the same time, not all Thunderbolt devices are certified for Windows. On Intel's Thunderbolt Community site, the issue is clearly stated

A Thunderbolt device may not function properly or at all if attempted to be used with an operating system for which the device has not been certified.

Recently, I spoke with a storage engineer with experience in Thunderbolt developement (he declined attribution). In order to ship a Thunderbolt device, manufacturers must first get their products certified. This is a process that consists of strict testing by three parties: Apple and Intel, as well as an independent testing laboratory, such as Granite River Labs in Santa Clara.

Some devices are certified as only Apple OS X compatible; and some are compatible with both Windows and OS X. So, a Thunderbolt device may be certified, however, it can show up as invisible to some Windows computers, since the PC BIOS may refuse to recognize a device without the Windows certification bit set.

Customers should note, the engineer said, that Thunderbolt-checking BIOS was only implemented on one or two models of Windows PCs that implemented Thunderbolt last year.

The newest models of Thunderbolt equipped computers that use Redwood Ridge controllers have a new implementation of the BIOS that presents a dialog to the user when a Thunderbolt device is first connected:

- if a device is NOT Windows certified, user is asked to confirm whether use should be permitted. User is expected to then have the proper Windows driver installed for proper operation or there may be problems with hot-plug and surprise removal.

When Thunderbolt was under development, Windows 8 was also under development, and the feeling at Microsoft was that there were simply too many unknowns to burden Windows 8 schedule at the time.

With the release of Windows 8.1, the situation will improve, he continued. However, "note well again, there is nothing in 8.1 to improve the Thunderbolt situation yet."

With Boot Camp, Apple can do a lot, but they can't fix deficiencies with Windows. That is still up to Microsoft.

I am interested in the Thunderbolt announcements over the past couple of weeks at the Intel Developer Forum (IDF) and IBC 2013 in Amsterdam. Many are Windows-certified systems aimed at the high-definition video-editing market. For example, ATTO Technology announced Thunderlink adapters and ThunderStream RAID controllers for Thunderbolt SANs.

Hewlett-Packard announced several Thunderbolt-compatible systems, including the ZBook 14, which the company calls the world's first "workstation Ultrabook," and the "first line of workstations to offer Intel's Thunderbolt technology for high-speed data transfer." They are due in October.

That "first workstation" claim must be news to Apple and the users of Thunderbolt-equipped MacBook Pro and iMacs.

The questions for Mac users is where is the Mac Pro? It wasn't on display at IDF, I understand, nor at IBC. We're all waiting.

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