What part of my computer do I need to upgrade to fix the lag?

Bailout1

Honorable
May 11, 2013
15
0
10,510
I've been trying to run Arma 3 today and even on low settings I can't play it at all. This isn't the first time I've had issues with running games without lag, which component do I need to upgrade or is there something else that might be wrong? Any advice would be great.

Computer specs:
Processor: AMD Phenom(tm) II X4 830 Processor 2.80 GHz
Ram: 6.00GB
Graphics card: ATI Radeon HD 5450
Hard Drive: 1TB
Screen resolution: 1920x1080