Samsung knows that some Galaxy S6 and Galaxy S6 Edge devices are experiencing performance problems. The good news is that it’s working to fix their issues.
Certain handsets appear to be mismanaging RAM. It’s not the amount of RAM that’s the issue – both handsets have 3GB – but it seems to be that the 3GB is filling up too quickly. This causes some applications to close.
When apps are used, they store information in the device's RAM for quick access. When that information is no longer needed, it is deleted from the RAM. This leaves space available for other apps and services to use.
It looks like the issue is that the Galaxy S6 and S6 Edge are having trouble clearing the RAM, causing it to fill up. But Samsung is aware of the bug and is working on micro-updates to solve the problem.
Samsung Mobile UK posted on Facebook: "Micro-updates are in the process of being rolled out to correct issues relating to device performance and stability... Keep checking for these on your device via Settings > About device > Software update > Update now".