Your pagefile will tell you first.

Yes, your system will show clear signs.

Open Task Manager and watch Memory usage. If it sits above 80-90% while you’re doing normal work—browser tabs, Slack, maybe a VM—you’re pushing the limit. But the real tell is the pagefile.

Windows uses the pagefile (swap file) when physical RAM is full. If you see that file growing into gigabytes and your disk activity spikes whenever you alt-tab, your RAM is the bottleneck. Performance will feel sluggish, apps take forever to open, and your computer sounds like a jet engine from constant disk thrashing.

Another sign: you start closing browser tabs like they’re going out of style. If you regularly work with multiple virtual machines, 50+ Chrome tabs, or large datasets (photo/video editing, compiling code), 16GB gets eaten fast. Games don’t usually need more, but creative workloads do.

Don’t wait until your computer is unusable. If you see sustained pagefile usage above 8GB, upgrade to 32GB and breathe again.