This is the fastest CPU for AMD's FM2+ socket. It's a quad-core 3.7/4.0 GHz CPU based on AMD's Steamroller architecture.
It's the successor to the Piledriver-based X4-760K (3.8Ghz/4.1GHz), and it should be around 10% faster, as well as running cooler: http://uk.hardware.info/reviews/5156/43/amd-a10-7850k-kaveri-review-amds-new-apu-steamroller-vs-piledriver
The 760k is outselling this chip on Amazon and is more expensive, so a lot of people making bad purchasing decisions!
Basically this chip beats the £50 G3258 quite easily, but it doesn't match up to the £86 Core i3-4130.
For benchmarks/reviews - this is identical to the A10-7850K, priced at £111.34, but there is no GPU.