8 GB or 16 GB — How Much RAM Do You Really Need?

Memory — RAM — is the desk the laptop works on. The disk is the cupboard where everything is kept; the RAM is how much can be spread out in front of it at once. When the desk fills up, the machine starts putting things back in the cupboard and fetching them again, and that is when everything slows down together.

So the question is really: how much do you spread out at once?

Before anything else: are you actually choosing between 8 and 16?

A great many used laptops are sold with 4 GB, and that is the decision people get wrong far more often than the 8-versus-16 one. 4 GB is filled by a dozen browser tabs and a video call, on its own, with nothing else running. It was reasonable a decade ago. It is not reasonable now, and no processor rescues it.

If the machine in front of you has 4 GB, the only two sensible responses are to add memory or to look at a different machine.

What is on your desk

These are the things that genuinely consume memory, in rough order of how often they are the culprit:

• Browser tabs. Each one costs memory, and some cost a great deal — a video, a map, a heavy web application. Twenty tabs is a real load.
• Video calls, especially with screen sharing. A class or a meeting plus the browser you are presenting from is often the heaviest thing a normal machine does all week.
• Accounting data. Billing software holds the company's data in memory, so the load grows with how many years of history the business has.
• Design and video software. Photoshop, CAD, editing. These are memory-hungry by design.
• Virtual machines and Android emulators. These take a fixed slice of memory and do not give it back.

Everything else — documents, spreadsheets, PDFs, music, watching a film — is small.

The answer

8 GB is right for browsing, documents, email, online classes, video calls, billing and accounts on ordinary data, light photo editing, and study work for most courses. This is the majority of people, and 8 GB is not a compromise for them. It is enough.

16 GB is worth paying for if you keep twenty-five or more tabs open as a habit, if you program with an editor and an emulator or a virtual machine running, if you do design or video work, if your accounting file is large or several years deep, or if you routinely run two heavy things at the same time.

Here is the part people misread. More memory than you use makes nothing faster. It does not speed the machine up; it stops it slowing down when you are working hard. If you never fill 8 GB, 16 GB will feel exactly the same — and the money would have done more as an SSD, or as a newer processor generation.

And if the choice is ever between 16 GB with a mechanical hard disk and 8 GB with an SSD, take the SSD without thinking about it. That is not a close comparison.

How to see what a machine has, and whether it can be added to

On Windows, press Ctrl + Shift + Esc to open Task Manager, choose Performance, then Memory. It shows how much is fitted, how much is in use right now, and — the useful part on a used laptop — a line reading Slots used.

"Slots used: 1 of 2" means there is an empty slot and the memory can be increased later. "1 of 1" means it is full, and the only way up is to replace what is there. On some thin and light models the memory is soldered to the board and cannot be changed at all, which the same screen will not tell you — that one needs the exact model number and a search.

This matters when you are buying. A business laptop with a spare slot is a machine you can improve in a year for very little. A soldered 8 GB machine is 8 GB forever, and should be judged as such on the day you buy it.

Leave Task Manager open for a few minutes while you use the machine normally, too. If memory sits above about eighty per cent with your usual work open, you are already short.

In short

Do not buy 4 GB. Buy 8 GB unless you can name the thing that needs 16. Check whether there is a free slot, because that is what decides whether the answer has to be right today.

Memory is not one of the ways the catalogue is split into pages, so the filter chips on the catalogue itself are the way to narrow by it — every laptop's own page lists what is fitted. The complete guide to buying a used laptop puts this in order with everything else worth checking.