It also depends on your GPU as previous post mentioned. I was able to try out DayZ on different machine than my home PC this weekend. My home PC is Intel core 2 duo E6550 @ 2.66, GPU Nvidia 8800GT. Work PC is Intel Quad Q6550 @ 2.83, GPU Nvidia GTX260. The rest is pretty much the same. There was a quite huge difference from what I've seen and played throughout the weekend (although not even on high details, the FPS went from ~25 to ~40) Imho it's playable on your mentioned machine, however some lag should be expected - thus, it ain't that ok:)