How do I test if upgrading my RAM actually made a difference?

Don’t use synthetic benchmarks — they barely test RAM capacity. Instead, open your heaviest real workload (Chrome with 40 tabs, video editor, VMs, big Excel file) and check Task Manager or Activity Monitor. On 32GB, you should stay under 80% memory usage with no swapping to disk. For a controlled test, time the same heavy multitasking session before and after — the improvement shows in responsiveness, not a number. If your machine stopped stuttering, the upgrade worked.