Some phones advertise “8 GB + 4 GB virtual RAM” or “RAM Plus”. That does not mean the phone has 12 GB of real memory.

What it is

Virtual RAM (also called RAM Plus, Memory extension or RAM expansion, depending on the brand) uses part of the phone’s storage as an overflow area for apps that are not in use. It lets the phone keep more apps ready in the background.

Why it is not the same as real RAM

RAM is very fast memory. Storage is much slower. When the phone moves data to the storage area and back, it takes longer than reading real RAM. The result is a small benefit at best, not the speed of a phone with more real RAM.

When it can help

• You switch between many apps and the phone reloads them often.
• You have plenty of free storage to give up.

When it does not help

• Heavy games and apps that need real, fast memory.
• Phones with very little free storage: the borrowed space is then taken away from your photos and apps.
• Phones with only 2 to 4 GB of real RAM expecting flagship behaviour.

How to check or change it

Look in Settings for RAM, Memory, Battery and device care, or search for RAM Plus or Memory extension. Some phones let you choose the amount or turn it off. Changing it may need a restart.

What matters when you buy

Compare real RAM in the spec sheet, not the total with the virtual figure added. See how much RAM and storage you need and how to read a phone spec sheet. To see what your own phone has, use how to check your phone’s RAM and storage. If the phone feels slow, try how to speed up a slow phone before changing memory settings.