Fundamentally it’s GF104-derrived, sporting the 48 CUDA cores per SM design that GF104 pioneered. But while NVIDIA did end up removing 1 of the 2 GPCs (and by extension, half the CUDA cores), they didn’t halve the ROPs and memory controllers while they were at it. As a result GF106 is a bit more than we bargained for, entering the world as a 192 CUDA core part but with 3 sets of memory controllers and ROPs, for a combined total of a 192bit memory bus, 384KB of L2 cache, and 24 ROPs. Internally this is organized as a 1 GPC part containing 4 SMs, resulting in GF106 having 1 Raster Engine and 4 Polymorph engines; meanwhile the contents of each SM remains unchanged from GF104, so for each SM there are 48 CUDA cores and 4 texture units (for a total of 16 texture units in GF106) along with its Polymorph Engine.
But like GF104, GF106 won’t immediately be seen in its full form. NVIDIA is launching their desktop GF106 cards with 1 of the 3 sets of memory controller/ROP pairs disabled. As a result GTS 450 as we know it today is going to be a 192 CUDA core part, but using a 128bit memory bus with 256KB of L2 cache and 16 ROPs. For the time being the only product that’s been announced that will use a full GF106 GPU is the GeForce GT 460M, which will be available in a 192bit configuration with all 192 CUDA cores enabled.