Steam memory leak after game quit

If the steam process itself is the one with the high memory usage then you need to report it to Valve, we might be triggering it by doing something different to other games but the bug would be in the steam client itself if the steam client leaks memory like that. But first do check your process monitor to confirm that ONI is actually closed and not, say, hanging around in the background leaking memory itself.

4 hours ago, nome said:

But first do check your process monitor to confirm that ONI is actually closed

No, ONI is closed. No process and steam library is happy to open it again. Opening it again stops the memory leak (for whatever reason..).

I will see if anything can be done through steam support then. Thank you!

Let me know what you find out, that one is super weird so I'm curious!

22 hours ago, nome said:

Let me know what you find out, that one is super weird so I'm curious!

Welp... sorry to disappoint you but Valve answered me it's a "me" problem since no one else have reported something similar with steam app or the game. Either hardware or software on my pc is failing and creates a memory leak. Not that I didn't know about that but now it's confirmed 

So .. .before I try reinstalling the game (because I am not going into a witch hunt of all the other probable causes and I already reinstalled steam) is there something I could check?

How big is your save file / do you have steam cloud(cloud saves) enabled / does disabling cloud saves modify the observed behavior?

7 hours ago, HarryMcCleave said:

How big is your save file / do you have steam cloud(cloud saves) enabled / does disabling cloud saves modify the observed behavior?

• Save file doesn't matter. Opening any save or making a new one and closing the game, will make steam have a leak. Even just opening the game and closing it, will make steam have a leak.
• I disabled cloud saves.. a couple years ago (unstable internet doesn't like them and I don't play on a second pc anymore) but I will check if any still remain

Do you think it's related to save files though? I can move all current saves elsewhere. I guess retired colonies folder too? Or will that break anything?

My understanding is you are experiencing the following:
After exiting ONI, the steam process appears to develop a memory leak (increasing size of committed memory to steam) until crashing.
We don't have an explanation for what this could be, however one guess was that something was going wrong with steam attempting to upload the saves to the cloud thus the question, at the moment we don't have another hypothesis.

26 minutes ago, HarryMcCleave said:

something was going wrong with steam attempting to upload the saves to the cloud

My cloud saves folder only has a "steam_autocloud.vdf" file. I assume that's a game file, right? Is there somewhere else connected to cloud saves in the game and if there is a cloud save in limbo (the other pc that I was playing ONI on is a win8.1 so steam stopped working there), is there a way to clear steam cloud?

26 minutes ago, HarryMcCleave said:

After exiting ONI, the steam process appears to develop a memory leak (increasing size of committed memory to steam) until crashing.

Correct

Edit: Actually the timing is correct. I used that old pc to open the game offline somewhere in the start of September '24 (was surprised it would even open but I hadn't opened that pc since the start of 2024) then around the middle of September I noticed steam crashing every time I closed the game.
I guess one solution is to never close the game again 

Edited September 17, 2025 by sakura_sk

I may jinx it.. but I will say it.
My steam doesn't memory leak anymore after closing the game and I don't know why...
It got to a point of no crash, just eating RAM until there was no more RAM to eat. The last couple of days seems like it stopped doing that. I will still monitor the behavior but I think it's not happening anymore..?