Microsoft is promising full support for USB 3.0 in Windows 8.
In the latest installment of the company's new "Building Windows 8" blog, Dennis Flanagan, the director of program management for the Devices and Networking group, discussed the need to support the latest high-speed flavor of USB despite certain difficulties in getting there.
Introduced in 2008, USB 3.0 offers not just faster transfer rates over previous versions but also better power management and battery life.
Citing data from research firm In-Stat, Flanagan noted that by 2015, all new PCs will come with USB 3.0 ports, while more than 2 billion USB 3.0 devices will be sold in that year. As a result, the decision to support USB 3.0 in Windows 8 wasn't a hard one. But at the same time, retaining backward-compatibility with all the older USB drives out there proved to be a challenge.
"While we were focused on building support for USB 3.0 chips inside the PC, we couldn't ignore the world of devices," Flanagan wrote. "We had to think outside the box - literally. There are over 10 billion USB devices worldwide. Some are in use daily and some are tucked away collecting dust, but all were originally designed to work with Windows PCs. Compatibility is the Windows promise. Our customers have grown accustomed to expecting new versions of Windows to work with their existing devices and drivers."
Microsoft's approach was to design a totally new USB software stack, or set of components, for the new USB 3.0 controller but keep its existing software stack for older controllers and devices. To forge ahead as early as possible with its testing, the company relied on virtual devices before there were any actual USB 3.0 devices to test.
But then when it came to testing actual devices, the company clearly couldn't check out 10 billion different ones, which meant the brute force testing approach was out of the question. Instead, Microsoft was able to break down the range of USB devices into around 1,000 unique ones that it's since been testing in its Windows labs.
The company also created its own customized testing software, known as MUTT (Microsoft USB Test Tool), which it uses internally and is sharing with hardware partners to find and fix any problems in new USB devices.
With USB touted as a plug-and-play technology, Windows 8 users will expect their USB devices to work out of the box, something that clearly drove Microsoft in its development of the new USB 3.0 support.
"Perhaps the most important aspect of USB 3.0 is the expectation that customers have of USB: it's just USB3 so it should just work, right?" Flanagan said. "Each and every USB device, low, full, high, and SuperSpeed, has to work in Windows 8. That's our focus while also delivering the most robust and reliable USB stack."