Back in Alpha, and Beta builds, i didnd't have much issue's with lag. But now, years later, it's worse than ever, this is ONLY in Multiplayer. Some mods are active, yes, but it's still never been this serious.
Now, the lag only happens during a few actions, or interactions. I will list those now, i'll keep this straight forward.
When i say Lag, i mean Zero FPS Stutters. It freezes, and then un-freezes in quick, few second manners.
This studdering happens when...
-First Loading In Server (expected, but not for long periods of time)
-When Zooming in while aiming down sights
-When Zooming in while aiming down Fixed Wing HUD
-When suddenly coming into unexpected CQC situations, and both players simultaneously look at each other and hold down the fire button. (even worse when trying to aim down sights first)
-When flying a jet or heli towards an object, the closer you are to said object nearing impact, the game will start to Stutter. Not sure if this is an issue with calculations, but it always freezes or stutters close to crashing into anything.
-And a little less common stutter, happens when aiming at enemy players. This one is random. Not sure why this occurs.
These instances are all the ones i can think of at the moment. The servers i usually play on are Sa-Matra Wasteland servers. Back in Beta, i never used to have stutter problems, at all. Now, i'm not sure what the cause can me. If this isn't enough information, i highly suggest play testing.