The size of Windows updates has long been a contentious matter, with complaints about how long the files, often hundreds of megabytes in size, take to download on normal, suburban, internet connections. A fascinating post on the Microsoft IT Pro Blog by software engineer Jonathan Ready tackles this, and details how Microsoft has been working to reduce the size of the update downloads.
It all comes down to new compression technology, which has allowed Microsoft to reduce the size of Windows 11 downloads by 40%. Ready, rapidly gets technical about the forward and reverse differential compression used in Windows 10 since version 1809, and why a bidirectional delta approach to compression gains very little efficiency.
The important thing was to cut download sizes without increasing installation time, or for IT managers to have to make configuration changes. The new versions of files have to be delivered to the target machine, and a path back to the original state needs to be kept so the patch can be reversed. This leads to both the new data and the old data being stored.
The new approach uses an ‘observation’ of the patch application step to generate the reverse path, meaning the data that would have been stored is no longer needed. As you might expect from the IT Pro blog, the language used is highly technical, but it’s an interesting window into the kind of thinking Microsoft is putting into Windows 11 essentially making it more user-friendly and easier on your bandwidth. With 20 million Americans living without high-speed broadband (and many, many more across the world), efficient patch distribution is an important step in keeping all our computers and networks secure.