3870->4870 had even held to the same 55nm process but it really was like 36% increase. But that I believe was more what GDDR5 brought, AMD even surprised themselves... The good old days when those who first jumped on the GTX260 found their AIB’s feeling obligated to print reimbursement checks! True, one might figure CuracaoXL offering about 25% above a Tahiti Ghz, while holding to a similar if better efficiency. Figure 10% from increase Sp and TMU’s, while there's conceivably something from alleged 50% increase in ROP’s. Weigh in low leakage production (Malta) parts curtail power usage, possibly even while presenting 10% increase in clocks. All that while on the same or close to the same 28nm die size, so conceivably for a $500 MSRP. That places it about par with a 780 working from a chip that is 30-35% smaller than the GK110, for like 28% less money. But seems it just won't come soon enough... Had AMD had them last May such printers might have ran agian.