The Windows Storage and Deployment Team which is responsible for storage APIs, Storage Sense, setup, and servicing to your phone, tablet, laptop, and desktop today detailed how they are giving Windows 10 a compact footprint. Windows 10 uses an efficient compression algorithm to compress system files and the recovery enhancements have removed the requirement for a separate recovery image.
With current builds, Microsoft estimates that they can give back 1.5GB of storage for 32-bit and 2.6GB of storage for 64-bit Windows using these new techniques. Also, they have redesigned Windows’ Refresh and Reset functionalities to no longer use a separate recovery image. Read about it in detail below.
Windows uses compression when it is helpful:
To ensure compressed system files do not adversely affect system responsiveness, Windows considers a number of factors when assessing whether a device should use compression or not.
One important factor is the amount of memory (RAM) a device has. The amount of RAM a device has determines how often it retrieves system files from storage. Another important factor is how quickly a device’s CPUs can run the decompression algorithm when retrieving system files. By considering these and other important factors, Windows is able to assess if a device can use compression without reducing human-perceivable responsiveness.
Since a diversity of Windows devices exist, Windows 10 performs this suitability assessment in the upgrade path. If compressed system files will give you storage capacity back without compromising your device’s responsiveness, then upgrade will automatically compress Windows 10. For new Windows 10 devices, manufacturers perform the suitability assessment and enable system compression appropriately.
On the topic of compression performance, we conducted extensive analysis and tuning for the first iteration of system compression (called WIMBOOT, we have a little more to say about WIMBOOT further below). Windows 10’s iteration of system compression retains that performance tuning and gains the advantage of tuning and enablement based on performance data from in-market devices. System compression enablement through software means Windows can adapt as the device landscape evolves.
Not only does Windows 10 intelligently use compression to keep the system footprint efficient, Windows 10 also uses compression to keep store apps’ footprint small. When compression makes sense for a device’s system files, it also makes sense for its apps. Because of compression, you will have more spare capacity for store apps and the store apps themselves will use less capacity.
In summary, system compression enables Windows 10 to provide capacity savings where it is important and without compromising human-perceivable system responsiveness.
Recovery is lightweight and efficient:
Without a separate recovery image, the Refresh and Reset functionalities will instead rebuild the operating system in place using runtime system files. Not only does this take up less disk space, it also means you will not have a lengthy list of operating system updates to reinstall after recovering your device.
Even though Windows no longer requires a separate recovery image, Windows can still recover a device from severe corruption. With Windows 10, you can create your own recovery media and back up the pristine state of the operating system and preinstalled software. If things go wrong and you are unable to refresh or reset your device successfully, you can boot the device using recovery media and reset to the prior pristine state.
Read more about it here.