Why RAM optimizers make your PC slower
The “free up memory” button in most optimizer apps actively hurts performance. Here is what it does, why unused RAM is not wasted RAM, and what to do instead.
Written by the team building AppFreeze, focus your PC on the task that matters.
Search "RAM optimizer" and you will find dozens of apps with a big button that frees up several hundred megabytes of memory. The number goes down. It feels like it worked.
It did not. In most cases you just made the next few minutes slower.
What that button actually does
Almost every one of these tools calls the same Windows API:
EmptyWorkingSet, or SetProcessWorkingSetSize with a size of -1.
A process's working set is the portion of its memory currently resident in physical RAM. Emptying it does not delete data or fix a leak. It tells Windows to page that memory out to disk — to your SSD — and mark the RAM as available.
So the number in Task Manager goes down. The data still exists. It is simply now on a storage device that is orders of magnitude slower than RAM.
The moment the application touches that memory again — which for anything you are actively using is within seconds — Windows has to fault it back in from disk. You have converted fast memory accesses into disk reads, and paid the write cost on the way out.
On a laptop, you also just spent battery doing it.
Unused RAM is not wasted RAM
The deeper misconception is that free memory is good. It is not. Free memory is memory doing nothing.
Windows deliberately uses spare RAM for the file system cache and for SuperFetch/SysMain prefetching. That is why a fresh boot feels slower than the same machine an hour later: Windows has spent that hour filling RAM with things you are likely to need.
A "memory optimizer" that drives your free memory up is throwing that work away. High memory usage on a healthy Windows machine is the system working correctly.
When memory genuinely is your problem
None of this means memory pressure is imaginary. It is real, and it looks like this:
- Sustained hard faults. Open Resource Monitor → Memory and watch the Hard Faults/sec column. Consistently high numbers mean you are actually short on RAM.
- A process whose private bytes grow without bound. That is a leak. The fix is restarting or updating that specific application, not a global cleanup.
- Commit charge approaching your commit limit. Visible in Task Manager → Performance → Memory. This is the number that predicts trouble.
Note that none of these are fixed by emptying working sets. Two of them are fixed by identifying a specific misbehaving process; the third is fixed by buying more RAM.
What to do instead
- Find the actual culprit. Task Manager sorted by memory, or Resource Monitor for the detail. Browsers with many tabs and Electron apps are the usual answer.
- Restart the offender, not the machine. A leaking process releases everything when it exits.
- Check startup programs. Things you never use, resident since boot, are a permanent tax. Task Manager → Startup apps.
- If it is persistent, add RAM. 16 GB is a comfortable floor for general use in 2025. This is unglamorous advice and it is usually correct.
What we are building
We are working on AppFreeze, and it deliberately does not have the button people come looking for.
The reason is the distinction this whole article circles: "my PC feels slow" is rarely a memory-capacity problem. It is contention — thirty background apps asking for CPU time while the one you actually care about waits its turn. Emptying working sets does nothing about that, and charges you the disk reads to page it all back in a minute later.
So AppFreeze goes at the contention instead. It notices which app you are working in, steps everything else down a scheduling priority while you are busy, and puts every one of them back exactly as it found them the moment you close it. No memory gets freed, because freeing memory was never the fix.
If a one-click number-lowering button is what you wanted, the good news is that the app already exists — several dozen of them, in fact.
Part of a full breakdown of what actually slows Windows down and what to do about each cause.
The same instinct — install a utility to fix something the system already handles — shows up in file management too. What a file organizer does is deliberately honest about which jobs are worth a tool and which are not.