Sylvia, thanks a lot for your answer. I posed the question due to an investment decision, so unfortunately I don't have the machine here yet to run the diagnostic tool.
For me it is important to know that I can operate the RAM modules with 1866 MHz because that speeds up extensive mathematical calculations I am planning to do significantly.
In detail I was planning to equip the corresponding machine with the i7-4930K CPU, the ASUS X79-Deluxe Motherboard and either 32GB (G.Skill F3-1866C9Q-32GXM) or maybe even 64 GB RAM (G.Skill F3-1866C10Q2-64GZM).
Unfortunately I cannot find reliable information if that is possible. My online shop of trust as well as my local hardware dealer are skeptical, although these components actually should go well together.
Maybe my concern is a bit to specific for the Intel forum, nonetheless I would be happy if someone who had a similar issue or is running a machine with comparable components could provide some advice on this.
Thanks,
Frefi