I currently am building a Mini-ITX system for gaming and general-use, and was wondering whether the extra two cores were needed or not.
I use my system for gaming, productivity, and occasional game recording/video editing. My current chip is an AMD FX-8150, which I cannot use in my ITX because for some reason, no-one makes Mini-ITX AM3+ boards.
It would help to know your budget.
My budget for CPU is around $200. I am currently considering the i5-4440.
I would advise you to go for the i5, but only if you can do it without making any compromises with other components, especially the GPU.
Quad core is generally the way to go with 99% of modern games excluding some indie titles and retro gaming.
If you don't plan on overclocking, buy a non K Intel part (It's presence denotes the ability to overclock).
Haswell may not be the best for you, deals can be found on 3rd and even 2nd gen Intels right now.
If you wanna save a bit of money and still get 95-99% of the in game performance, go with a less recent generation.
Depends on the GPU. I assume through you indicating that you're only getting an i3 or i5 due to not being able to use the Bulldozer chip in a mini-ITX rig that you already have a GPU on hand. If it's a relatively high end GPU, say anything better than an HD 7870 or 660 Ti, then you'd want the i5. If you have a GTX 660 or HD 7850 or lower, the i3 should do fine without seeing any bottlenecking or anything.
Look up some gaming benchmarks - I seen benchmarks showing an Athlon II X4 950K supporting an HD 7950 just fine putting out almost as good framerates as an i5, though in really demanding games like Metro it really took advantage of the better CPU. So depends on the game and whatnot but the Haswell i3s are really fast, the i3-4340 (3.6GHz) is better than the FX-4300 and slightly slower than the FX-6300 (in multi-threaded performance).
For gaming it should be fine, but if you've got the dough for an i5-4430, then why the hell not? The i5-4430 is about the same as the FX-6300 in multi-threaded performance, would come close to your 8150 (assuming you had it running at stock).
A quad-core CPU would not really help for gaming as most games aren't threaded that well (can't use multiple CPU cores). However, for video editing and recording, it would definitively make a difference. The i5 4440 you'r e looking into is nice, as long as you're not planning on overclocking.