Original Link: http://www.anandtech.com/show/4942/windows-8-to-use-less-memory-than-windows-7
Windows 8 To Use Less Memory Than Windows 7by Andrew Cunningham on October 7, 2011 4:00 PM EST
One of Microsoft's stated goals for Windows 8 is for it to run on any system capable of running Windows 7, which at a minimum will require the its resource usage to remain the same as its predecessor's. Today on the Building Windows 8 blog, Microsoft's Bill Karagounis details how the company has worked not just to maintain memory usage relative to Windows 7, but to reduce it, with an eye toward making it run acceptably on ARM-based tablets that lack the beefy processors and multi-gigabyte RAM banks of today's PCs.
One improvement to the memory manager allows it to search for duplicated items in memory, and to unload all but a single copy to save space (the Windows installer and image deployment tools for enterprises do something similar to reduce the size of the install media, keeping one copy of a given file and a record of everywhere that file needs to go on the hard drive rather than, say, five copies of the same file). Another allows developers to designate certain parts of programs and processes as "low priority," meaning that when the OS needs more memory it can maintain system responsiveness by removing those less-important bits from RAM first.
The OS's other major memory-saving trick comes not from reprogramming major programs and services, but changing how and when they run. Many services in Windows 8 - Windows Update, the Plug and Play service, and others - run only when they're needed, while in Windows 7 they run in the background more or less constantly. By changing some traditional Windows services to run only when triggered and making many new-to-Windows 8 services behave the same way, the OS can save RAM without actually shedding features.
For more, Microsoft's blog post is as always more exhaustive and detailed than what we've reported here - it's linked below for your convenience.
Source: Building Windows 8 Blog