What peaks my interest here is the idea of the GT212, that we previously thought would be a pretty simple refresh and simplification of the GT200 architecture, getting a 60% increase in shaders – moving from 240 to 384. Another important feature change listed here includes a move from a 512-bit memory bus to a 256-bit bus. While this might at first seem like a dramatic shift backwards the table also lists GDDR5 as the memory format used and that would help alleviate any bandwidth drops with the 256-bit bus while allowing NVIDIA’s engineers to keep the chip design smaller even if transistor counts go from 1.4 billion to 1.8 billion.
Our source indicates that the number of stream processers increases from 240 (GT200) to 384, and the number of TMUs also increases to 96. Such improvements are fairly significant, kind of like 128 SPs of G92 to 240 SPs of GT200. As the second-generation rendering structure, GT200 features 10 TPCs, and we’re wondering if GT212 would follow this structure. If so, GT212 will feature 16 TPCs, and there’re only 6 TMUs in each TPC, while there’re 8 TMUs in GT200. GT212 is very likely to adopt the third-generation rendering structure – each TPC contains four SMs and 8 TMUs, and there’re 12 TPCs, so there’re 12*4*8=384 stream processors in total.
Generally speaking, the stream processors of GT212 increase by 60%, but TMU just increases by 20%.
The memory interface of GT212 will reduce from 512bit to 256bit, which is quite similar to AMD RV770. GT212 will aslo use GDDR5 to make up the loss of memory interface. The memory clock frequency of GTX280 is 1107MHz. If the memory bandwidth of GT212 has to achieve that of GT200, its data rate must be above 4.5GHz.The new products are usually superior to previous ones in specification, so the data rate of GDDR5 is supposed to be around 5GHz. NVIDIA and AMD both use GDDR5 on their middle-end lineup, which makes us to worry about the productivity of GDDR5.