Is the 3820 better in rendering and gaming that the 3770K? Also are their any benefits with one compared to the other?
There are benefits. Personally, I would go for a 4770k if you want the mainstream socket, or wait for a 4820 if you want the extreme socket. The 4820 will be the same price as the 3820, but be based on the Ivy cores, so it will have 40 lanes of native PCIe 3.0, native USB 3.0, and the benefits in per-core performance that you saw with Sandy to Ivy.
i totaly agree with Brennanriddell, i would go for the intel 4770K or wait till the new 4820K. the reason why i would not go for 3770k anymore is because, the its eol, and the z87 chipset has some cool feutures. en good board choices.
i would go for the 4770K if you are plan to go with a single gpu setup, because the mobo´s on Z87 are mostly cheaper and nicer feutured, but if you plan to go on multiple GPU setups then i would go with i7-4820K.
When is the 4820k suppose to be out?
It was originally leaked as Q3, iirc, so, if I am told correctly by the internet, soon.