I think I address some of your points in the article. I specify that overall peak power consumption for the chip is 30W - this is for an octa-core configuration. This means one CPU roughly consumes 3.5W (if you take out the coherency manager and fabric). Then I also referenced the SPEC CPU2000 performance number at 1GHz. From that you can easily calculate performance per W. If you want more technical details about the architecture, they do have an user manual here http://www.loongson.cn/uploadfile/cpumanual/Loongson3B1500_p...

I also state that a new processor will be released next year and it will run at above 2GHz which should solve the difference in frequency.