780 DCII is mostly aimed at quiet and efficient operation for air-cooled builds (hence that awesome cooler).
For watercooling I'd probably say Classified is the way to go if you're looking to really push overclocks. You can either buy Classified and attach blocks yourself, or look for Classified Hydro Copper
. But keep in mind I'm not exactly an experienced guy lol, I've never gone into watercooling.
Just going by Hexus's review of 780 Classified:
The Classified is as primed for overclocking as any air-cooled card we've come across of late. Running past Nvidia's voltage blocks can be achieved in two ways: use the optional EVBot hardware or opt for software-based tweaks. We decided to use the latter by harnessing a program called GTX Classified Controller popularised by the guys over at Overclock.net.
Classified Controller allows us to raise the GPU's voltage to a maximum 1.3875V, which when allied to the maximum power target of 115 per cent and 94°C temperature target should make for great overclocking. Trouble is, there's a fine line between voltage (power) and GPU throttling. Playing around with the voltage and examining performance gave us the optimum combination of 1.2875V and maximum in-game speed.
The end result? A base clock of 1,218MHz and memory at an effective 7,678MHz. Yet base clocks, as we have shown, are semi-meaningless. Running the card through our games highlighted that the core ran at a steady 1,384MHz when at full chat. Yup, that's fast.
Air simply wouldn't be able to achieve those insane volts / clocks, only waterblocks could do it.
Lightning (and HOF) would probably be aimed more towards extreme
overclockers looking to break records. I don't know much about Lightning/HOF blocks.
Anyway I recommend asking in an actual watercooling thread before making any decisions Edited by Tippy - 10/28/13 at 11:30pm