That rumor is pure crap concerning the R680, it's a rumor that's about the upcoming R700. The rumor was that R700 will use 4 of the same chips and every chip would be a single stop on the ringbus-memory controller, just like R520/R580/R600/RV670 have 4 main stops on the ringbus internally, but this time each separate chips will be one of those stops.
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