[2.0.60] Flip occasionally spiking to high usage causing brief drops in UPS

[somepersondontask]

07-18-2025, 18-31-16.png (22.2 KiB) Viewed 676 times

I've had this issue for months now, going back several versions. I don't know what causes it and it happens with VSYNC on and off. The save I attached in my previous bug report exhibits this behaviour (just disable the scrap handling setup as it was causing unrelated issues with my UPS.)

My specs are as follows:

CPU: Intel i5 10400
GPU: RTX 2060
Motherboard: B560M-A
RAM: 16GB
Storage: 2TB SSD

I genuinely do not know what would cause it. It first started shortly after I first installed mods and has persisted through every iteration of my mod folder and through every save I've started since then.

[somepersondontask]

After some testing in my current save, I can somewhat consistently reproduce the Flip lag by zooming in and out of areas with coverage that haven't been loaded in a while.

[pioruns]

Check your RAM and swap usage.

[somepersondontask]

Usage is stable while Flip lag persists.

[pioruns]

You mean zero swap use? RAM usage is sitting at what value while playing?
Next, I assume you are playing on Microsoft Windows operating system:
1.Please check Windows Event Viewer, System tab, for any errors.
2. Reinstall GPU drivers, make sure to use most up to date version.

Nothing else comes to my mind which could slow down your game, sorry. Maybe your base is so big CPU isn't handling it, haven't checked your save. Please pin URL with your save in the first post, to make work easier for Factorio developer looking at this report.

[somepersondontask]

07-21-2025, 13-20-26.png (160.35 KiB) Viewed 510 times

This is a snapshot of memory and the Event Viewer. Flip lag occurred several times during this.

I've attached my up to date save.

I highly doubt my base is the issue since Flip lag was occurring before I even left Nauvis. Even now update only takes ~2.5ms.

My GPU driver is up to date.

[pioruns]

I think it's the RAM. You have too many programs open. Your RAM use it at 88%, it probably means, swap is being used too. Open Task Manager (not Resource Monitor), I think there you can see swap use. Swap is an "additional RAM" on the hard drive, much slower by definition, OS is using it when RAM is full (like yours is).
It is possible that, with your RAM being fully utilized, Factorio have to wait for certain assets to load back to RAM, and you are experiencing UPS/FPS drop while it happens.

To test it out, you should close everything and unload all icons from system tray, then try to play Factorio, while monitoring RAM.

[somepersondontask]

07-21-2025, 18-45-28.png (1.2 MiB) Viewed 438 times

This is only with Factorio, Steam, and Lightshot (what i use to take the screenshot) active. Everything else in the system tray is disabled. I am still getting Flip lag.

[pioruns]

My guess was right, it's the RAM.
Your RAM is completely exhausted (100% allocation), hence you experience problems. This is not Factorio's fault.
Still no Task Manager screenshot from you, so can't tell how far you go above physical RAM allocation.

[somepersondontask]

What do you want to see from task manager and resource monitor? Going to do another snapshot once I know what to show.

[pioruns]

What do you want to see from task manager and resource monitor? Going to do another snapshot once I know what to show.

07-22-2025, 06-58-41.png (380.35 KiB) Viewed 343 times

Screen like this (pulled it out of search results) will show your physical RAM and allocated memory. I don't use Windows, so there may be a better tool.

[somepersondontask]

07-22-2025, 11-02-22.png (1.02 MiB) Viewed 281 times

Snapshot with only Factorio, Steam, and Lightshot active in the system tray, everything else closed.

[pioruns]

I may be wrong, but my calculations are as follows:
In your image:

Committed: 18.0 GB
RAM in use: ~14.1 GB

So, approx. 3.9 GB swap/pagefile is being used. It means, you are 4GB short. Your system is constantly thrashing 4GB onto your HDD/SSD. Everything will be slowing down regularly while loading memory contents from your storage. I think Resource Monitor is showing this, Hard Faults/sec, this is measurement of data not being found in memory and system needs to fetch it from swapfile.

You need to further disable hogging applications (antivirus? run Factorio directly with no Steam?), or upgrade RAM.
Maybe tweak Factorio settings to reduce RAM usage? Crank all graphics down?

[somepersondontask]

Steam servers are shitting themselves so I won't be able to test for a bit.

For now, I've found that disabling texture streaming and setting the texture quality to low seems to have mitigated a majority of the flip lag I was experiencing though it is still present to some degree. I will continue experimenting with the graphics settings to see if I can mitigate it further. For now, I'm unsure as to why Factorio is using so much RAM that it's causing itself to slow down.

[pioruns]

Steam servers are shitting themselves so I won't be able to test for a bit.

For now, I've found that disabling texture streaming and setting the texture quality to low seems to have mitigated a majority of the flip lag I was experiencing though it is still present to some degree. I will continue experimenting with the graphics settings to see if I can mitigate it further. For now, I'm unsure as to why Factorio is using so much RAM that it's causing itself to slow down.

Factorio is using exactly the amount RAM it needs. It's your operating system that is transparently allowing applications to use more RAM than you have, by swapping onto the hard drive. Without swapfile, if you run out of RAM, you run out, Factorio crashes. What Windows is doing it's a mitigation to a hardware resource problem. Every application and game would work the same way in this case.

Consider upgrading RAM to 32GB if you can, or work on decreasing RAM usage.

[somepersondontask]

Workshopped the issue with a few others and I've managed to pinpoint the problem.

My GPUs VRAM is not big enough to store the maximum size texture atlas, which causes it to dip into system memory to cope (her words not mine). Reducing the texture atlas size to 4096 has resolved most of the flip lag: now it's not as frequent and peaks around 15ms.

[pioruns]

Glad you were able to mitigate it Well done. Is your GPU 6GB VRAM?

[somepersondontask]

Yes, it's an RTX 2060 with 6GB VRAM. Prolly the best I'll have for a good while.

[pioruns]

See if you can upgrade that RAM though To add or replace a stick shouldn't be as drastic as full GPU upgrade.