What's more important are the timings. Both are good but you should go with highest speeds with
lowest timings. If you have memory installed already, there are more things to consider (like the
operating voltage on the modules). I have 4x HyperX modules. 1 GB each. A pair of PC9600 needing
2.3V and a pair of PC8500 needing 2.2V. The voltages may be slightly off but at least they are different.
Kingston is good so I manually set the speed to PC8500 (1066 MHz) and the voltage to 2.2V for both
pairs. With just the PC9600 pair, I managed to get CL3 timings which is very good. Can't get them that
low with an additional pair.