Hi FLAM,
As both cards have 2Gb of VRAM the short answer in my opinion is NO.
Have a look at the System requirements at http://www.x-plane.com/2016/11/x-plane-11-system-requirements-announced/
Others who have asked a similar question to you have been advised to go for the "recommended" rather than the minimum requirements when upgrading. If and when you do upgrade go for the Nvidia card instead of an AMD card for better performance. The general concept is a 1070 card but others also go for the 1080 card.
X-Plane 11 is GPU, CPU and RAM reliant for best performance ie all three rather than just one component.
If you haven't purchased X-Plane as yet download the demo version and try it with your current setup. It just may work to your satisfaction.
When I purchased my dedicated X-Plane PC to run XP10 I had a Nvidia GTX780ti card and have now upgraded to a GTX1080 card for XP11.
On the basis you have a PC rather than a laptop the benefit is that you can progressively upgrade components as when funds become available.
Hope this helps
Glenn