What we know is that the 1- and 2-port 100 G cards use the Typhoon ASIC. To get enough bandwidth separate ASICs are used for input and output. Knowing the ASIC is a hint that buffering is similar to other Typhoon line cards. But probably not the same.

The graphic below helps with the relationship between Trident and Typhoon and shows one of the 100G cards on the bottom right.

Announced in 2014, a more powerful RSP and spiffier Network Processor code named Tomahawk will support 8-port 100 Gig line cards. Not a lot of info. This slide is from a Feb 2015 deck: