Factorio Forums

summary: the fps stays above 60 (about 110) but hitches and drops when the game speed is set to 2. ups stabilizes at 120.

this happens with all mods disabled.

my setup, not sure how much is relevant but here it is:
graphics: radeon rx 580 graphics card, driver version 19.8.2 (adrenalin series drivers)
windows 10 pro
cpu: amd ryzen 5 2600 (6 core, 12 thread, 3.4ghz base)
ram: corsair vengeance led 16gb (2x8GB) 2400mhz ddr4
multiple displays connected. one at 4k 60hz, the other at 1080p 60hz.

given:
all mods disabled
factorio 0.17.68 installed and running

steps to reproduce:
1. start new game, vanilla settings
2. open debug mode and enable the fps/ups viewer and other relevant stats
3. move around in-game (fps and ups should stay at 60)
4. run `/c game.speed=2` twice (once to trigger the achievement warning, and another time to actually set the game speed to 2)
5. move around in-game.

expected: fps stabilizes at 60 or below, while ups stabilizes at 120 or below.

actual: fps "jumps" up to 120, and ups jumps to 120. in addition, when moving around, the actual fps seems to drop and there's massive frame skips and jumps.

note: strangely, when unfocusing from the game (clicking somewhere else, alt tabbing) the fps stabilizes back to 60 and the ups to 120. in this situation i can even set the game speed to 100 and with the game unfocused the fps will settle at 60 and the ups at 6000. but once i focus on the game (click anywhere on it), the fps jumps to 110 and the hitches start, and the ups drops to about 3000.
note: this didn't seem to happen a few versions back, like back in 0.17.5x or 4x. i'll test some more and update when i know exactly which version this started on.
another note: i'll try to record some video of this behavior with obs's record function. i may post a link to it here once i obtain that.
log file: https://pastebin.com/1xZuL5PE
screenshot with good performance (60/60): https://snipboard.io/bY9BlT.jpg
screenshot with strange/bad performance (106.3/120): https://snipboard.io/CKgRiM.jpg

edit: tested while recording with OBS, and there were no performance issues at all. i could not get it to happen again while recording. even with OBS just open, the performance drop didn't happen. but the moment i closed obs, then factorio started hitching.

edit+update: ok so i just updated my graphics driver to 19.9.1 and did some windows updates and i can't seem to reproduce the issue. not sure if it was because i rebooted or because i installed the updates. for now.... i guess disregard this bug? until i update it again.

Since FPS and UPS are tied together this is to expected, same happens in the other direction if you hit simulation cap (ups and fps drops). On faster speeds performance issues would show up faster and more noticable.

Try to disable "Use flip presentation model" in the graphics options (and restart the game).

thank you! i'll try those suggestions out and experiment a little bit when i get home from work. though i'm disappointed that i couldn't reproduce the issue the last time i checked.