ArmA2 / OA (low) performance issues

[ArmA2 / OA (low) performance issues]

i have no idea where to get that information

[ArmA2 / OA (low) performance issues]

ok so i get low performance when im on the ground, but when i fly its like my comp went super, no lag, any explanation or help to fix ground performance? my comp specs are:

processor: Pentium® dual-core CPU E5800 @ 3.20 GHz 3.20 GHz

RAM: 3 GB

system type: 64-bit operating system

OS: win 7

any help is appreciated