There's a lot of mixed information on this forum about 2133mhz ram in the Skylake iMac. The questions that need to be answered are: 1) Will the Skylake iMac boot and operate properly with 2133mhz ram. 2) Will 2133mhz ram run at 2133mhz in the Skylake iMac? Or will it only show as 2133 in the system profile - all the while running at 1866? Here is a stick for consideration, at $65 it's very reasonable priced: http://www.amazon.com/gp/aw/d/B00UV...X110_SY165_QL70&keywords=Kingston+hyperx+2133 I have a Skylake iMac arriving Oct 22-27, so if no one has real test results by then, I'll volunteer to be the guinea pig for everyone. Thanks!