What memory speed access for i5 4590/4690 namely

[AlterMind]

Hi All,

I'm considering building a new upper-mid-range computer for mixed use (incl gaming).
I thought settling for an i5 of the 4590 or 4690 type as their base clock speed is starting at 3.5 or 3.6 GHz and would chose the Asus Z97 type of motherboard (socket compliant), as they accept RAM speed up to 3.2 GHz and was considering the rather affordable 2133 MHz DDR3 RAM.

But while looking again at Intel's website for these processors (and even the Broadwell, 5th generation) I see almost everywhere in the "Memory Types" field the following : DDR3 and DDR3L 1333/1600 at 1.5V which is way below the 2133 I was counting on.
On Intel's site I see almost no i5 (or even i7) displaying higher than the 1333/1666 memory type. Am I getting something wrong here ? Can I get the i5 I selected above to work with the 2133 DDR3 at their full speed or it be trimmed down to 1666 at best ?

Thanks for your advice !

 

[AlterMind]

Or 1600 even.
I think you need a 'K' chip to handle 2133+ ram speeds,tho I would hazard a guess this is the point meaningful gains fade except for specific apps.
Afterthought; I doubt those locked chips on board ram controllers will run faster than 1866 anyway, best to buy the Gskill sniper 1866 and try for the overclock to 2133

Thanks for the response. The weirdest of all is then that even for the 4690K type (the overclockable one I understood) also displays the same 1333/1600 memory type on Intel's site ! Does that make any sense !?

Update: thinking even further on your comment that I'd need an overclocking CPU type to benefit from the full 2133 RAM speed, I don't understand why that would be the case : if at 3.5 GHz the RAM isn't efficiently used up to its 2133 MHz, why would it suddenly at 3.9 GHz ?

 

[AlterMind]

More simply speaking, how can you effectively enable 2133 MHz RAM on a MB claiming to rise up to 3200 MHz clocking when the memory type featured by the cpu is limited to 1333/1600, as it seems to be the case for the vast herd of intel i5/i7 cpu's ? (if you exclude the very few i7 at the top of the Xtreme edition)

Looks to me that enabling the XMP profile will just make the MB optimise access to RAM but actually the CPU won't really benefit from it. Right ?