Bought ARMA 3 a few days ago, and have just started trying it this weekend.
Stumbled on this list of very useful tweaks to increase FPS. The original list is over at Armaholic: http://www.armaholic.com/forums.php?m=posts&q=21465
Arma 3 CPU Optimization
1. Go to Steam Library
2. Go to “Arma 3″ Right Click then select “Properties”
3. Select “Set Launch Options”
4. Copy and paste the correct launch command line below to what your system is setup for and click “OK”.
For AMD CPU users:
AMD Dual Core with 4GB System Ram:
“-noSplash -cpuCount=2 -high”
AMD Quad Core with 4GB Ram:
“-noSplash -cpuCount=4 -high”
AMD Six Core with 4GB Ram:
“-noSplash -cpuCount=6 -high”
AMD Eight Core with 4GB Ram:
“-noSplash -cpuCount=8 -high”
If your running more than 8GB Ram then apply this to the end of the launch line:
This will allow your game to utilize 8GB system Ram instead of 4GB.
For Hyperthreaded CPU’s such as a Quad Core you will apply this:
This will enable your Hyperthreads on your CPU so your CPU will act as an eight core when running Arma 3.
If you are running a Hyperthreaded Six Core then:
If you are running a Hyperthreaded Eight Core or Eight Core Xeon then apply this:
If you are running just a non Hyperthreaded CPU such as a Quad Core then select “4″ instead of “8″ same for a Dual Core you will select “2″ instead of “4″.
All AMD CPU’s are NOT Hyperthreaded so Hyperthreaded options is highly not recommended as this can cause system failure or damage.
I will not be responible for system failure and damage if you choose to select more cores then you have on your command line!
makes your operating system prioritize services and processes to run your game better but this can cause system failure and instability if you dont have a good running system. If you Overclock this can cause system instability.
disables startup videos and advertisements.
enables extra CPU cores and Hyperthreads.
when set to “6144″ (6GB) and up lets your game use more system Ram then 4GB.
Do not set to higher than 4GB if you dont have at least 8GB. You can set to “8192″ (8GB) if you have 12GB+ Ram.
Compliments to Badoosh!
another excellent parameter is
set to 5 if dual core
set to 7 if quadcore or greater
it lets the game run additional rendering threads to help compliment the cpuCount parameter
oh, and you can set a custom memory allocator. it had a decent impact on frames in Arma 2, but i haven’t tested it much in Arma 3.
not sure if BI released any newer allocators, but so far TBB4 has been their best performing for both Intel and AMD processors.