Hi, I just threw 8GB of 1333MHz DDR3 into my Mac Mini (2,66GHz). It seems to recognize it correctly as 1333MHz, but I guess the bus speed of 1066MHz limits it anyway. If the RAM would run on 1066MHz, it should show up on System Profiler, shouldn't it? http://browser.primatelabs.com/geekbench2/view/265076 It don't know whether this is known yet, or brings any advantage because of the bus speed. Things are blazing fast compared to 2x1GB 1066MHz, just for the record It should come with 2x2GB as default, as the cost for DDR3 reduced in the past anyway. 2GB is just insufficient, even for minor simultaneous daily tasks. Regards Edit: According to Geekbench they are as fast as the original ones. Maybe 1066MHz 7-7-7-20 are even faster, because these are 1333MHz 9-9-9-24 and there is no faster timing available.