Thank you for your reply.But what I want to say is that the performance of my computer configured as gtx770 in 2014 is not much different from that of the current gtx1070ti in arma3.
Why the FPS of game runtime is sometimes very low, but the system resources are not completely occupied.(i7-8700k 16G 1070ti ,,,game FPS:40 , CPU:40% , Memory:78% ,Disk:1% , GPU:52%)