So Going by Core counts and clocks alone:

TAHITI - 7970/R9-280X = 2048*2*925 = 3.8 TFLOPS
TONGA - R9-380X = 2048*2*970 = 3.973 TFLOPS
HAWAII - R9-390/290 = 2560*2*1025 = 5.248 TFLOPS
POLARIS- RX-480 = 2304*2*1266 = 5.838 TFLOPS
HAWAII - R9-390X/290X = 2816*2*1050 = 5.913 TFLOPS

POLARIS- RX-480 = 2304*2*1500 = 6.912 TFLOPS
Fiji - R9-Fury = 3584*2*1000 = 7.168 TFLOPS
Fiji - R9-FuryX = 4096*2*1000 = 8.192 TFLOPS
Fiji - R9-Fury Nano = 4096*2*1000 =8.192 TFLOPS

Now you have to take into account the core improvements from GCN 1.0 (Tahiti), 1.1 (Hawaii/Tonga), 1.2 (Fiji), 1.3 (Gen 4/Polaris)

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