Look at basically everywhere including official statements from 2013. GPU is clocked at 853 MHz. That's just 6.6% though.
CPU was clocked from 1,6 to 1.75 GHz, 9.4% more.
http://www.eurogamer.net/articles/digitalfoundry-xbox-one-gpu-receives-speed-boost
https://www.techpowerup.com/gpudb/2086/xbox-one-gpu.html
http://www.extremetech.com/gaming/156273-xbox-720-vs-ps4-vs-pc-how-the-hardware-specs-compare
Not that it's such a big difference. The Xbox One GPU would need to clock at 1.2GHz to have the same floating point output.







