Microsoft’s Dona Sarkar broke the news in a blog posting concerning the release of Windows 10 Mobile Insider Preview Build 14977:
We are getting ready to start releasing PC builds to Insiders using UUP. To prepare for this, we are going to pause all PC builds for both the Fast and Slow rings starting this evening (Friday 12/2). We will begin flighting the latest builds via UUP starting with our internal rings first then to Insiders based on each ring’s promotion criteria. We’re excited to be able to release builds for PC to Insiders using UUP! Mobile builds are not impacted by this.
Microsoft first announced the UUP (Unified Update Platform) in early November, and it brings a number of new features to Windows 10 that makes retrieving the latest updates more efficient. UUP uses differential downloads to dramatically reduce the package size for updates on both PC and mobile platforms. “This will eventually be impactful for PCs where users can expect their download size to decrease by approximately 35% when going from one major update of Windows to another,” wrote Microsoft’s Bill Karagounis in November.
UUP also makes checking for updates more efficient, reducing the amount of data that is sent to the client and processing times required, since the actual Windows Update service determines which updates are needed. These performance benefits will make a much larger impact on Windows 10 Mobile users than those using Windows 10 on PCs.
Microsoft has also made the OS upgrade process for those running Windows 10 Mobile easier and more in line with what takes place on the PC. “On your phone, we would sometimes require you to install in two-hops (updates) to get current,” added Karagounis. “With UUP, we now have logic in the client that can automatically fallback to what we call a ‘canonical’ build, allowing you to update your phone in one-hop, just like the PC.”
The Insider Preview builds of Windows 10 Mobile have had UUP support baked in since November, so we should see the functionality move over to the PC side once Microsoft hits the “resume” button.