[EDIT: Yes. It will run Arma. Will you also find yourself asking, "Why do I still see this game running poorly at times?". Yes. This is why all the tips on pushing one particular setup, or part - such as the CPU, PSU, or Hard Drive.] i7 all the way, bro. Price difference is nothing compared to longivity. Arma by itself pushes hardware, but then you add mods that further push certain things, sometimes graphically as in Blast Core Visuals or JTD Fire and Smoke, and you have that much more overhead. Arma PR is way cool, the few servers I tried, I chose populated ones - over 40 players all in different vehicles or whatever - A battlefield with a lot going on. It pushed my system to where I had to manipulate my view/draw distance in Video Settings to get my desired frame rate. In Arma I'm used to keeping my view distance at around 5000 meters, 10,000 is max (fyi). If I have ~50 FPS, I call Arma very playable, with max everything - shadows, etc. It's the dip you want to avoid, don't want that dropping below 30FPS ever. That means an over-capable CPU, Motherboard, and RAM pairing. Poffadder has led several discussions on this very topic, and as a 2nd year PC Science/Engineering student, I will go with the exact configurations he recommends, or would use himself, as his knowledge is so very current and backed by a proper education in the field right now. We all know Arma streams data off the Hard Drive like mad when playing, that's why we all suggest running Arma off it's own SSD on a separate SATA channel on said Motherboard. 60-80GB should be fine for most Arma players. For enthusiasts hoping to DL tons of mods (kiwirambob, I'm lookin at you!) you want to get a 120GB at least. Either way, well worth it. This option, you can upgrade to as well. It is no difficult thing to re-install Arma at a later date to see this improvement. Figure ~30GB for Arma and ~20GB for a couple extra maps and mods like PR ALWAYS have a little breathing room on hard drives, i.e. empty space.