Indeed, we were surprised to see 2.38V modules running at at 1.3GHz, but the explanation arrived earlier today.
While talking to the Corsair crew, we learned that all of the Dominators are tied speed-wise to the lowest targeted denominator, which means there may be still a lot of performance left in the modules. Performance does not only mean running at the highest possible clocks, but also achieving clocks with uncommon voltage settings. The design of Dominator modules enabled Corsair to make one interesting product announcement: Corsair Dominator PC-10000 modules.
PC-10000 modules are hitting the streets in Q107
These modules are guaranteed to work at 1.25GHz with latencies CL5, 5-5-18-2T, but that is not the highest clock you can reach. Robert Pearce and the gang are demoing the modules working in pairs with an overclocked Core 2 Duo E6300 on 437.5MHz QDR FSB, the marketing number being 1.75GHz. When they went with 2.5V setting, a latency of 5-5-5-18 was achieved.
Corsair watercooling and power supply, EVGA motherboard with the cheapest Conroe - 1.313MHz memory clock
However, the way these modules are being manufactured pretty much guarantees you a price premium over other Dominators. Still, if you want the fastest memory on the block (until competition launches comparable modules), you will be able to get these 1.25GHz modules clockable to 1.31GHz. ยต