If your vmnetx3 is showing 10Gbps in your guest, this is working like expected, since vmnetx3 is an 10gbps adapter and not matter the speed of your physical link, the speed inside of guest will show 10Gbps but of course if your VM need communicate with devices outside the host, the maximum speed will be 1gbps if your physical adapters are at 1Gbps.
See more about: How can I be connected at 10Gb when I only have 1Gb adapters in my hosts?
---
Richardson Porto
Senior Infrastructure Specialist
LinkedIn: http://linkedin.com/in/richardsonporto