My latest kit is RipjawsZ F3-17000CL9Q-16GBZH 16GB ( 4x4GB ) 2133 9-11-10-28 1.65V from renewed series ( I mean different IC than in older kits and label with info that it was tested on the Z87
). Manufactured in September 2013.
Inside we can find Samsung HCK0 IC
This RipjawsZ kit can generally make 2800 10-12-12-28 1N ~1.86V but my X79 motherboard doesn't really like anything above 2400 ( possible to stabilize but sometimes at much higher VCCIO/SA ) and it ended up at 2672. Below results on GB Z87X-OC and MSI X79A-GD45 Plus.
4770K / Z87X-OC - 2800 10-12-12-28 1N
4930K / X79A-GD45 Plus 2672 10-12-12-28 2N - my board also isn't working with CR1 , at all .. but I think it will work at CR1 on some other boards
It's also working at 2400 9-11-11-28 1N / 1.68V or 2600 10-12-12-28 1N / 1.75V.