Thanks kyosen-san.

Here's the crack so far.

Tech Report review showed Barcelona scaling more than 100% in performance in comparison to core speed in a few cases. Because it's not just core speed we're talking about, but L3 cache speed/latency and IMC speed.

SPI/Cinebench 10 (incl. S7s old 8-core CB tests)

2GHz K10 39.750s - 2.4GHz K10 32.672s
(2GHz) 8 cores/DDR2-667/NB1.6GHz CB 1907/12941 - 4 cores/DDR2-800/NB1.8GHz CB 1984/7709

SPI Scaling
20% clock change ((2400-2000)/2000 x 100)
17.8% performance increase ((39.750-32.672)/39.750 x 100)

17.8/20 x 100 = 89% scaling