If gaming on integrated graphics, go with the 2133mhz sets, as this will be faster for that, but otherwise they should tie with the 1866, so that's no big deal, really. (Note: lower number in box is better)
If gaming on integrated graphics, go with the 2133mhz sets, as this will be faster for that, but otherwise they should tie with the 1866, so that's no big deal, really. (Note: lower number in box is better)