In Android on phones, a lot of RAM is used to keep apps in memory so you don’t have to restart them (saving a lot of processing and I/O power). There are several layers of cache built into the system.
My phone currently uses 3.3 GB for apps and about 2.7 GB for cache (temporary file caches, kernel cache, apps saved in memory, etc.). It also uses about 900MB of swap (I suspect that’s zram but I’m not sure).
What will this be spent on? Most of it goes to apps (currently Fluffychat is the largest cache out there, but that’s because Firefox is cached). Next comes the system server and other systems and Google services that are necessary for the device to function properly. Each app service running in the background uses about 120-200MB of RAM, and I have plenty of that.
Does it all use RAM it is necessary† No, probably not, it’s very useful for developers to use a heavy abstraction layer like Flutter to build cross-platform applications.
For the same reason that Windows doesn’t really need 4GiB, the Android subsystem shouldn’t need additional 4GiB. Windows probably needs to emulate the Linux kernel by default and run the Android framework in the background, even if you’re not running Android apps, so it will cost you 2GB of memory. Insert a few big Android apps or games and soon you will have 3-4 GB. Combine that with your existing Windows apps (which use at least 4GB of RAM, as per Microsoft requirements) and you’ll soon have 6-8GB of RAM. Keep in mind that in addition to applications, Windows also needs to keep a few gigabytes of cache active for things like memory mapped I/O.
There is a difference between “works” and “works well”, and “works well” you have to do more than just meet the minimum requirements. Microsoft is clearly aiming to “do well” this time around. We’ve all seen what happened when Microsoft assured people that Windows 7/8 was running fine with a single 1GHz CPU with 1GB of RAM, meaning the whole system was very slow. The slightly broader system requirements are in my opinion a welcome addition, especially for the optional features.
I’d rather see 8GB be the minimum requirement for all Windows to finally get rid of needlessly expensive mid-range laptops, but that’s going to take a few more years I’m afraid.
