If you had watched the keynote at //build conference, you probably still remember the slide that compares the memory usage on Windows 7 and Windows 8 side-by-side. The amount of RAM reduced is quite obvious, if not significant, which is a very good sign to anyone who still wants their old machine in production. And now the Build Windows 8 blog posted some details what’s behind-the-scene reasons and facts.
Here are some highlights worth noting:
- The runtime memory usage of Windows 8 is an important factor in determining the Windows 8 system requirements, as well as the broadened spectrum of devices that will host Windows 8.
- To meet the goal of having the same system requirements as Windows 7, an important task is to make room for new functionality, and reducing memory usage is one of the rooms they can make.
Memory room to make
- Memory combining – a technology in which Windows efficiently assesses the content of system RAM during normal activity and locates duplicate content across all system memory. and that saves 10s to 100s of MBs of memory.
- Service changes and reductions – a new "start on demand" model introduced on many services like Plug & Play, Windows update, as well as many new functionalities makes a lot of savings on memory.
- Doing the same job w/ less memory – complete separating "hot" parts of memory (those frequently referenced) from "cold" parts densely consolidates the hot items, which brought down the overall runtime memory as well.
- Lazy initialization of the "desktop" – Windows will only initialize OS components unique to the desktop environment when necessary. This is another source of approximately 23MB memory right there. So guess that flipping back and forth between desktop and Metro UI is a nasty way of eating your resources.
- More granular prioritization of memory – with a better scheme for the prioritization of memory allocation in place, Windows can make better decisions about what to keep around and what to dump.
Something you may not realize before
- Microsoft is delivering the complete Windows 8 experience on SoC-based devices characterized by low power consumption. And minimizing memory usage on these devices can prolong batter life. – very good point.
- The extended Windows Defender technology included in a clean install of Windows 8 is also optimized for memory and resources use per Jason’s blog about protecting you from malware.
Obviously, all of these changes are very welcomed, and will put the new Windows 8 system on a wider range of devices without any compromising the performance. But here is one thing I would like to point out. If Windows 8 finally is made to target both tablet and desktop market, I wish the system can be more wise knowing what to approach when on tablets and what to use when on the desktop. By saying that, I want to see a lot of free memory space when on tablet because that would prolong the battery but would like to see most of the memory being used when on desktop because then I know my money invested on these memory isn’t wasted.