Cooler Master Shows Dual-Radiator Seidon 120D Liquid Cooler
Cooler Master has introduced a new style water cooler -- one that switches tradition around a bit.
Cooler Master is showing off a new type of water cooling radiator at Computex 2013, one that makes up part of the Seidon 120D kit. The Seidon 120D doesn't exactly stick to the ordinary water cooler design the way we know it. Instead of simply slapping a fan onto a radiator, Cooler Master has decided to sandwich a fan between two 120 mm radiators. Traditionally, it was more likely to sandwich a radiator between two fans instead.
With this design Cooler Master aims to greatly improve cooling performance. It claims that this design has the same cooling power as kits with 240 mm radiators, though it will be compatible with a lot more enclosures. It also claims that the fin design is optimized for better airflow, which likely means that the fin density is just lower. We can imagine that a fan sandwiched between two radiators with a very dense fin arrangement will have a lot of trouble moving air.
There was no word on the Seidon 120D's pricing or availability.

"With this design Cooler Master aims to greatly improve cooling performance. It claims that this design has the same cooling power as kits with 240 mm radiators, though it will be compatible with a lot more enclosures."
It won't have the same cooling as kits with 240 mm radiators: apart from the radiator thermal properties (material and size), cooling will depend on flow-rate and air temperature. RAD-FAN-RAD config will impose greater pressure drops on air flow, thus decreasing air flow-rate; air temperatures through the second radiator will be higher than the ones with the 2nd fan on a 240 radiator - this will diminish the heat exchange. Take in consideration that a second radiator may slow down the liquid flow, which deteriorates performance.
Note that spacers and 120x38mm fans will help to solve these issues to some extent.
Advantages of this will be that it may be installed on a single fan mount, and it also may be quieter. (now a days it is pretty easy to find a case that has 240 mouting options..)
Also, i have a config like this one, and even with spacers and 2 120x38mm fans, performance is below the one obtained using 240 rads.
Hope this helps