Originally Posted by b1gapl
The HZs are supposedly better for overclocking, because they use Micron D9 chips, which are very good for overclocking. I don't know much about the MQs and PQs though....but HZs for the win.
All of G.skill's other DDR2 677 and above modules use proMOS chips.
proMOS chips are a gamble becuase they are what the Corsair XMS2 use. These chips can come out to being highly overclockable (such as the HK's) or not overclock one mhz (like some XMS2 has been known to do).
The difference between G.skill's proMOS chips is that they are highly binned for overclockability before they are assembled therefore they are keeping their reputation as "The Ultimate OC" while still using cheap chips. My guess is that their slower proMOS chips goes into their DDR2-533 ram.
G.skill Chips known to use proMOS