Hi,
I'm going to assemble a new desktop PC (in my old one MB died).
I'll buy a AsRock Z77 Extreme4 as MB, 2x8 Gb DDR3 RAM G-Skill CL10 1866 (found an excellent price), and a i5 3570 or 3570K as CPU.
I don't look about overclocking, so the real difference is the video: HD 2500 for 3570 and HD 4000 for 3570K.
PC will be used for video editing (now I use Premiere CS5), not for gaming.
I'll take video card from the old PC, a Geforce 8500 GT 500 Mb.
What's the best config 
:
i5 3570K without graphic card
i5 3570 with graphic card
Using graphic card, are there difference between 3570 and 3570K (no overclocking)?
Thanks for your time
If you will be using a dedicated PCI Express video card, then you do not need the Intel Core i7-3570K. So the Intel Core i7-3570 should be OK.
OK.
And what do you think about Z77 Extreme4 and Pro4 MB?
There is a difference of 27.00 €.
Currently I cannot comment on third party products, but I would suggest contacting any of the Authorized Intel® Distributors and they will be able to provide you recommendations as well as pricing and availability information.
You can find a list of Authorized Intel(R) Distributors at:
www.intel.com/reseller
Last question.
I'll buy the i5 3570.
What do you think is the best choise of RAM:
2x8Gb DDR3 1600 CL9 (Corsair)
2x8Gb DDR3 1866 CL10 (G.Skill)
They have the same price (the difference is only 0.25 Euro)
Thanks
Since this memory 2x8Gb DDR3 1866 CL10 (G.Skill) is not supported by the Intel Core i7-3570 processor, I would suggest the 2x8Gb DDR3 1600 CL9 (Corsair), this is because the processor memory controller hub supports up to 1600 MHz, make sure to use memory running at 1.5 volts.
