Something that worked for me to reduce the LAG

[panzerschreck]

It is an advice made by a member of the CA team (post 4)

http://forums.totalwar.com/showthread.php/89151-I-have-to-unticked-1-of-the-cores-every-to-play-R2..it-is-ridiculous!

I changed this line in my preferences script: C:\Users\your name\AppData\Roaming\The Creative Assembly\Rome2\scripts

number_of_threads 0; # number_of_threads <int>, Set the number of threads <= 0 - automatic, >0 = explicit number #

to

number_of_threads 4; # number_of_threads <int>, Set the number of threads <= 0 - automatic, >0 = explicit number #

It reduced the lag for me even if I still have lags, but less strong. According what the guy said it could allow your CPU to use the others cores better. Hope it will help you too!

[A Barbarian]

Yes, this can help, although depending on the number of real- and virtual CPU cores the number should probably be different.

For me, using 'task managers' CPU affinity setting for Rome2 has helped me in some laggy situations. In those situations task-manager showed that one CPU core was a lot of time at 100% while the others were much less busy. After removing one core for Rome 2, the load was much better distributed over the cores and none of them showed more than 80% load. The lag disappeared.

Since CA is pretty inexperience in multi-core/multi-threading development, I think the engine sometimes runs into a situation where the threads go 'out of sync' and spend a lot of time waiting on each others results. The more threads you have, the more likely it is.

[Imperator of Rome]

Ermm, my game went from 15fps to 60 fps after I changed the threads value. Apparently it was using 1 thread when my processor could take 16. Sticky this. The game isn't exploiting your CPU.

[A Barbarian]

Which CPUs do each of u have?

Because when I tried to figure out what the automatic value was (by looking at the 'number of threads' of Rome2.exe in the taskmanager) it seemed that it actually used 4 for my 4770K 4-core CPU, although with hyperthreading it has 8 (4 real and 4 virtual).

I am using 8 as a setting for a while and works good for me. When I tried 6, the game repeatedly crashed during battle replays. So this setting can even influence stability.