Whilst I have always thoroughly enjoyed playing PC games, when it comes to PC's themselves I am actually pretty awful. I have no idea when it comes to graphics cards, memory, processors or anything past a basic level of understanding. What I used to do was walk into a shop tell a man what games I wanted to play, then ask him to give me a PC that I could happily play said games on then pay him. Sadly I am now an impoverished student and am unable to afford such luxuries. I have had some computer problems recently and had to put a new graphics card in, which I just straight swapped. Thing is that it wasn't running games overly well as it was, getting between 12 -25 FPS on DayZ (or 4 in elektro when getting shot) So I have been looking at building myself a new PC (steambox type affair) for under £350. I know some of you guys are very knowledgeable so thought I'd ask some opinions. I really need to keep costs down so here are my current specs in case anyone can see where I can upgrade.

Intel Q6600 Processor
(2.4GHz, 1066MHz FSB, 8MB Cache)
4GB Memory
1TB Hard Drive
512MB nVidia GeForce 9600GT Graphics card

The guy in my local shop suggested that I get a 9800 GTX+ graphics card at least, and need to get a 600w Power Supply Unit.

I fully expect some chuckling and knowing winks at my complete lack of PC knowledge, so if you could start off with helpful info, and then mock me that'd be great.

If DayZ/Arma is your most played game you are better off spending some more money on your CPU. ARMA is heavily limited by CPU performance and its a part you really can't spend enough on if you want to see FPS gains. The GPU is almost irrelevant. My i7 3770k with my old GTX 460 gives almost the same FPS as with my current GTX 680. Even if you don't have much money to spend on a beast CPU its worth spending more than that Q6600, look at an i5 or and AMD equivalent CPU.

Intel performance is a lot better than AMD on ARMA especially also, but of course the price is higher and if you're building a budget system you may want to see what AMD have to offer. In terms of graphics cards you pretty much get what you pay for, with AMD again offering better value for money than Nvidia. Other games like BF4 are going to call for the GPU more than ARMA. You can calculate your PSU requirements using a tool like this

http://www.extreme.outervision.com/psuc ... orlite.jsp

Is £350 your absolute maximum budget or is there the possibility of holding out a while longer so you can spend a bit more?
I have found, in my experience, holding out for another £50-£100 can be worth it.
If you are looking to upgrade one part then you may also need to change another because of compatibility. e.g. Upgrading to an i5 would mean you need a motherboard with the same socket (1150).
Then if your current setup used DDR2 RAM it would become obsolete because a newer more modern motherboard will likely only support DDR3. See where I am going?

If you want to purchase a more powerful GPU then the guy in the shop is right saying you will likely need a more powerful power supply but don't skimp on on this part. A cheap nasty PSU will inevitably fuck you over some day so spending that little bit more and getting a more reliable (not necessarily more powerful) PSU from a brand like Corsair is definitely worth it. But like the weed-dawg says, if you are just doing ARMA 2 then prioritze CPU over GPU.

In order to say whether things would be compatible a bit more information would be required about your current setup. You could use a tool like Speccy to find out more detailed info like your motherboard model and memory type and stuff and post the information back here.

If anything I have said here is wrong people, let me know.