I think that 1600 7-7-7 models of Geil are BBSE rather than PSC. You can check that out by looking on the side of ICs - BBSE have white stripes while PSC don't (A3G-P PSC also have stripes, but they're too bad for such spec).
With DDR3-2133 on Sandy Bridge, PSC run best on 7-10-7-27, BBSE at 7-9-7-24. Start with 1.8Vmem, 1.10Vccio, 1.15Vccsa and Auto subs and work your way down. There are also presets in the BIOS.