Hasewell-E CPU .

[sharantk]

It is found that, in the Intel's website the supported memory types for the i7-5820K are of DDR4-1333/1600/2133. My question is can I use DDR4 RAM higher clock speed than 2133MHz? If I can use does it improve the performance?

 

[Darkbreeze]

It depends on the motherboard. Intel's CPU specs never list all the supported module specs, only what was tested at SPD profiles. The 5820k can support higher than 2133mhz modules so long as they are compatible with the motherboard's stated specifications including voltage specs.

Performance between 2133mhz modules and 2400mhz modules will likely not be noticeable.

 

[Nuckles_56]

You can, but you will see a fairly insignificant improvement in performance in everything other than memory bandwidth limited programs

 

[i7Baby]

Most X99 can take XMP enabled DDR4 ram up to 3100MHz. But it's expensive. 2133 cas 12 is what you should look for. Best bang for the buck.