memory - Benefit from using 3400 MHz RAM on a CPU that's only rated for 2400 MHz RAM

Situation

I intend to buy a mainboard which supports memory speeds up to 3866 MHz. The processor will be an Intel i7-7700K, 4x 4.20GHz which supports memory speeds up to 2400 MHz. The CPU seems to be the bottleneck in this case.

Questions

• Is there any significant performance gain in buying memory which runs at 3400 MHz for this configuration?


• Will the system work at all and run stable if the memory speed is faster than the supported cpu memory speed?


• Could there be disadvantages with the higher memory speed?

Answer

Higher-frequency RAM is often via an overclocked profile (e.g. XMP) which you have to enable in the firmware settings. The only real downside is higher power consumption and a bit more heat if you enable it. Compared to buying lower-frequency RAM, you're getting a guarantee that your memory will be able to overclock to those frequencies, and a built-in profile that makes it effectively a one-click operation.

Note that the "2400 MHz" is just the standard memory frequency; it will go higher if you use the XMP profile (or manually overclock).

Worst case? You pay a bit more for the RAM but run it at the lower speed. No big deal.