Memory Speed Limits and your CPU

Razathor

Honorable
Jan 11, 2014
18
0
10,510
Hey folks, I've been trying to understand CPU memory limitations and just can't seem to wrap my noggin around it. I'll be using a Intel Core i7-4930K Ivy Bridge-E 3.4GHz 6 core, along with an Asus x79 Deluxe MB, and a 780 TI. I won't be overclocking any of the components, but as I understand it, the CPU allows 3 memory speeds up to 1866.... does this mean that I won't be able to use G-Skill Ripjaws with a speed of 2400? As the MB seems to list that as an option... fair to say I am a bit confused. :p
 
ASUS specifications allow up to 2800MHz, though anything over 1866MHz is listed as an overclock. This is most likely because there isn't any standard for DDR3 over 1866MHz.

EDIT: Actually, JDEC goes up to 2133 and XMP profiles cover all the rest, so ASUS is unclear in this one. Anyway, it should work as it is within specification.
 

Tradesman1

Legenda in Aeternum
Most all 4930Ks can run up through 2666 sticks, some can run 2800. In general, you might need a slight OC to run 2133 (say 16GB or more) and a higher OC for 2400 or 2666 of the CPU. Some 4930K can run 2133 w/ no OC, so in part in depends on your individual 4930K and how strong it's MC (memory controller) is....Basically to answer your question is you can more than likely run 2400 sticks with nothing more than a slight OC to to the CPU, which will be nothing more than changing the multiplier on the 4930K to 40 which will result in a 4GHz freq for the CPU
 

Razathor

Honorable
Jan 11, 2014
18
0
10,510
Thanks guys, RAM has always been a part of my systems I never paid too much technical attention to as far as trying to really understand it. All of these answers helped tremendously.