I’m planning to build a PC. I want to use this PC both for work (development, virtual machines), multimedia (watching high res videos, music, streaming content to my TV) and playing games like Battlefield 4.
I think that Intel Core i7 4820K and a decent x79 Motherboard with ability to beef-up RAM to 64 GB later would be better than Intel Core i7 4770K with 1150 Motherboard.
Could you please share your thoughts on whether or not my approach is fair and future-proof?
The big difference between the two chips is the platform. The 4770K sits on a completely modern chipset with lots of native current-gen I/O (SATA6, USB3, etc), while the 4820k lives with a two-year old chipset that has limited numbers of these same items. Conversely, the 4820k platform is far more robust; it has 2.5x as many PCI Express lanes and twice the memory capacity. Mainboard manufacturers usually add extra onboard controllers to make up for the lack of connectivity on these boards as well - resulting in an equal footing, at a higher price.
The other differentiating point is how the heat spreader is attached to the CPU die. On the 4770k, it is simply glued, making overclocking to high speeds difficult due to lack of direct thermal contact to cooling. The 4820K is soldered to its heat spreader, allowing for better cooling and in theory higher overclocks. Benchmarks on various sites have shown that at stock speeds the 4770K is slightly faster than the 4820k, but when overclocked with a closed loop water cooler, the reverse becomes true.
Bottom line, if you are going to tweak your system, the 4820k MIGHT be a better fit for you. If you plan on sticking with stock speeds, the 4770K is a better fit.
I don't have much expertise as far as how the other CPU operates, but the 4770k has been great for me. The overclocking could be a lot better, but i have no qualm with letting it sit at 4.2 ghz. I got the 4770k for $250 bucks at microcenter and the 4820k seems like it's $50-$100 more for a very small performance boost. Even if your budget is endless, I would rather take those savings and invest in a better GPU. If gaming is what you want than that's your best bet. That $50-$100 would be more wisely spent upgrading other components in your perceived build with a much better performance to dollar ratio.