Do you have a source for that?
https://arstechnica.com/gadgets/2017/03/amd-ryzen-review/
> Indeed, Ryzen's 95W TDP looks impressive compared to the 140W TDP of Intel's 6900K, a similar 8C/16T processor based on the Broadwell-E architecture. But in practice, Ryzen pulls just as much wattage from the wall as the 6900K, in some cases slightly more. Considering just how power-hungry Bulldozer was, that remains a significant achievement, even if it means that overclocking headroom isn't as high as some might have hoped.
https://www.bit-tech.net/hardware/2017/04/06/amd-ryzen-7-170...
http://www.tweaktown.com/reviews/8072/amd-ryzen-7-1800x-cpu-...
http://hothardware.com/reviews/amd-ryzen-7-1800x-1700x-1700-...
(bear in mind the 5820K/6800K/6850K are 6C, the 5960X/6900K are 8C, and the 6950X is 10C)
Essentially AMD is rating their TDP under a very light load - like a single thread at full boost clocks. Under an all-core load they are running roughly 30% over TDP. Intel's TDP rating is much more generous - they aren't quite rating at full, nonstop AVX load (eg Prime95) but typical full-load consumption is 15% under their TDPs which leaves some headroom for intermittent AVX usage.
Anecdotal evidence: my 10C20T Haswell-E Xeon pulls ~60% of its rated TDP during a Handbrake x264 encoding run. My 6C12T 5820K Haswell-E gaming chip (overclocked to 4.13 GHz all-core at stock voltages) pulls 75% of its rated TDP during a similar Handbrake x264 run. And supposedly x264 is smart enough to use AVX, so that should be a realistic-but-high figure. My OC'd 5820K pulls 90% of its rated TDP during a Prime95 SmallFFT run.
It's still a huge gain compared to Bulldozer - but not quite as rosy a picture as AMD is trying to paint. They are equal with Haswell-E/Broadwell-E in most respects, not 40% ahead like AMD is rating them.
AMD is playing the same game in the GPU market too. AMD's RX 480/580 are rated for "GPU only" TDP (which they define to exclude memory/etc) but NVIDIA rates the whole card. In practice, AMD is ~30% above their official TDPs while NVIDIA is pretty much spot on.
https://www.techpowerup.com/reviews/Sapphire/RX_580_Nitro_Pl...
(RX 580 is rated at 185W TDP, GTX 1060 is rated at 120W TDP)