Is this a good gpu??

Solution
Yeah, it should be at least a Bronze. But I still think you should be fine as long as you don't overclock your system.

For HD gaming in 1920x1080 in combination with this your Ryzen GPU this GPU will be perfect. Might even be overkill. A GTX 1060 would probably do it too but for that price you probably not doing anything wrong.
The PSU is borderline. For the GTX 1070 a 500W PSU is recommended. But it will be OK as long it is not a super cheap PSU and you are not going crazy on overclocking. I think you will be fine.

In regards to the question if its a good GPU that really depends on what you want to accomplish. What CPU do you have? What are you playing and in what resolution? Generally speaking the 1070 is a good GPU but not for someone who wants to play 4k on best graphic settings.
 
Yeah, it should be at least a Bronze. But I still think you should be fine as long as you don't overclock your system.

For HD gaming in 1920x1080 in combination with this your Ryzen GPU this GPU will be perfect. Might even be overkill. A GTX 1060 would probably do it too but for that price you probably not doing anything wrong.
 
Solution