Seems to me that the Volare V 3 , is a refresh of the xabre 600. The V 5 and the V 8 are based on the Xabre II. SiS said way back in Feb?, on their xabre roadmap that the xabre II would come in two flavours, one with 4 pipes and one with 8 pipes.
What is surprising is the dual chip config...