128-bit DDR2/GDDR3/GDDR4 memory interface
是記憶體的介面頻寬
Ring Bus Memory Controller
Fully distributed design with 256-bit internal ring bus for memory reads and writes
而Ring Bus Memory Controller 並非介面而是內部的控制器的頻寬
詳細說明請看Tom's 硬體指南
http://www.thg.com.tw/article_000099903.html