RAM is the desk; storage is the filing cabinet

RAM (memory) holds what the machine is working on right now and empties when the power goes. Storage (the disk) holds everything the machine keeps, whether it is on or off. 'Out of memory' and 'the disk is full' are different faults with different fixes.

Hone is a place to practise a career, one idea a day. This is one of its lessons, written out in full and free to read without an account.

What it is for

'My computer says it is out of memory' arrives, and somebody orders a bigger disk, because the user said 'memory' and the machine has 500 GB of 'memory' in the catalogue. The disk had 200 GB free. The RAM was 8 GB with a browser holding 6 GB of it. The word the user uses tells you what they feel; the two numbers tell you which one it is.

How to think about it

Two numbers, every time: RAM total and RAM in use, disk total and disk free. A machine with 5 percent of RAM free is slow and closes programs; a machine with 5 percent of disk free cannot save, update or start properly. Fix the one whose number is short. Closing programs frees RAM; deleting files frees disk. Neither does the other.

Worked example

RAM: 8 GB total, 7.6 GB in use → 0.4 GB free

Five percent free. Programs will be slow to switch and the browser will start dropping tabs.

Disk: 256 GB total, 190 GB used → 66 GB free

A quarter free. The disk is not the fault, whatever the word the user used.

Browser alone holding 5.2 GB of RAM

The one program with most of the desk. Closing forty tabs frees more than any cleanup tool.

After closing: 3.9 GB in use, 4.1 GB free

The number moved and the machine is quick. RAM was the fault; the disk was never touched.

Your turn

A user cannot save a file and the disk shows 2 GB free of 512 GB. Write which of the two is short.

Cannot save, 2 GB free → the  is short

The trap

Buying more RAM for a machine that is slow because its disk is 98 percent full. The disk needs room to breathe for updates and temporary files, and no amount of RAM gives it that.

Practise RAM and storage on HoneA question on it now, a coding challenge where there is one, and it is remembered for review. Free, no email needed.