I've been looking into benchmarking the performance cost of different ui mods, and made a minimal ui mod for this purpose.
('OnBeatTimings', uploaded to the mod vault.)
This tells you how long is being spent in UI 'beat functions', on average. (Not the total performance cost of UI mods, in all situations, but something which I think is significant, and which can be measured quite easily.)
To use this, run FAF windowed, open the log viewer and console, set up a benchmark situation, leave it to run for a bit (10 seconds or so) and then enter the following in the console:
This tells you the average time spent in beat functions which are not flagged as 'throttled', per update.
You can also get the average time spent in 'throttled' beat functions, with:
Note that these timings include time spent in built-in beat functions, as well as beat functions in mods you have enabled, but you can disabled and enable mods and see how this affects the timings.
To quickly set up a benchmark situation, I suggest enabling cheats and then using the copy and paste units thing. (So set up a situation with a load of units placed one time. Select the units. Hit ctrl-shift-C to copy placement script for these units. Paste that into a text editor. To place the units back into game for future benchmarking copy the buffer out of your text editor and then ctrl-shift-V in game.)
When looking into the timings coming out of this I found that one built-in beat function in particular, for 'avatar update', was taking a disproportionate amount of the time spent in situations I was benchmarking.
'Avatar update' is for the ui elements normally towards the top right of the screen that show things like ACU health and shield, number of idle engineers, and so on.
I made another 'micro mod', then, to simply remove this update function. ('DisableAvatarUpdate', also uploaded to the vault.) With this mod installed and enabled, the avatars no longer get updated, so no longer work correctly, but this enables us to quickly check the cost of this beat function, and also enables you to reduce your total UI beat function overhead quite significantly, if you are so inclined.
If anyone is interested:
- Have a go and see if you can repeat my findings (e.g. benchmarking beat function times with and without DisableAvatarUpdate enabled)
- Check the beat function cost of other ui mods you have installed (if there are significant performance costs for running popular UI mods then it would be good for people to know this)