Just curious here. I had a big issue with the game crashing both at start up and while playing any sort of matches.
I know this sounds unrelated but I am getting there....
Anyway, a lot of time programs crash due to the 0xc0000005 error because of permissions issues. So I decided to force Arma 3 to run as Admin, and then I went to my %AppData% folder and deleted the Arma 3 Alpha folder in order to kill the cache. Not only did this fix my crashing problem, but it fixed a whole host of other problems, and even increased performance in several areas.
Here is a short list:
No more crashing
Improved server list load time
Improved Role Assignment screen speed
Increased FPS in both Single and Multiplayer.
Here is my info:
Core i5 3570k @ 4.7GHz
16GB RAM @ 2044MHz 11/11/11/27 CR2
Gigabyte GTX 670 @ 1201MHz core, 6808MHz mem.
4TB RAID 0 config.
In game, everything is maxed out but AA.
Resolution is 2560x1440
4x FXAA
VSync is OFF
My FPS while playing Wasteland on a 30+ person server will fluctuate between 25-45FPS
CPU usage varies between 20-50%, does spike to 100% when it does its little launch benchmark.
GPU usage varies between 50-80%
In conclusion, it doesn't fix the issue, but it was definitely a big improvement from before I tried my little fix.
Clearly my GPU is still getting limited by my CPU while its stuck down at about 45% most of the time.
Anyway, try it and see if you notice any differences.