It all depends on the motherboard. Usually, if a reliable site tells you that a PC can use PC-12800, You can use any lower DDR3 such as 10600. Since the site says you have 10600 I would stay safe and get 10600 memory when upgrading. Make sure to get the right amount of channels, such as dual and triple channel. Powerful i7's use triple channel. Then the i7 860, i7 870, i5's use dual channel. Core 2 Quad/duo uses ddr2
Tell me if I'm wrong, since I built my own system and when buying the mobo it uses 12800.
Hope this helps