Hello,
I've recently bought new 16Gb (2x8 Gb) memory sticks. Their model is "Hyper-X 16GB DDR3 2400 MHz CL11" - HX324C11T3L2/16.
I've found that they're running at 1600 MHz instead of their 2400 MHz... I've searched around a bit, specifically a bit on these forums but all I've come up with...