nameless517

rx480

I would go with the 480, but i would pay the extra £20 for an 8GB one.

https://www.newegg.com/Product/Product.aspx?Item=N82E16814137082&cm_re=Rx_480-_-14-137-082-_-Product
 
149$ 
 
You're welcome

The FX processor is slower, but it wont matter that much.
Just go with rx480 or GTX 1060 if you prefer Nvidia.

The FX processor is fine for these GPUs.  I would go with rx480.  Micro stuttering is usually a CPU issue.  The 480 is a great card and continues to get even better with driver updates.

It will be fine 

My wife has this cpu with the rx 480 4gb and has no issues at all. Works like a charm. 

480 most likely unless the 1060 6GB is cheaper?

RX 480, I would never recommend Nvidia for low end cards. AMD supports their cards for significantly longer than Nvidia does, meaning they are better if you keep your card longer than one generation. I've used both Nvidia and AMD, and from my experience the only time I would recommend Nvidia is if A) You are like me and love EVGA customer support enough to sacrifice performance in the long run. B) Want high performance NOW and are okay with suffering later, or upgrading every generation or 2. This is apparent with my 780ti. In older titles, my 780ti performs about on par with a 1060. However, bceause Nvidia doesn't really optimize drivers for the "older" cards like the 780ti, it performs at about a 1050ti level in newer titles. AMD however, still supports the crap out of the 290x, meaning the 290x performs at just about a 1060/RX480 level in both newer and older titles, despite the 780ti being a faster card when they both launched. 
 
TL;DR: RX480 because AMD supports their cards longer causing better performance in the long run.

thats most likely the problem 

I find it strange that they tested it in front of you with both sticks in and it failed, but because it works with one stick they won't help you out.
I woulda raised the god damn roof until I either had my money, or another mobo.

With your RAM?
 
I'd just swap the RAM and sell the ASUS.

yeah, maybe RMA the board.

That unheatsinked and what looks like only 4+1 VRM is probably going to overheat like crazy

You arranged it in dual channel right?
you put the ram into the according colors, not neccesarily next to each otheroin this case you could put it into both greens.

I wonder why the gigabyte won't support that ram??? it should... have you tried running it in different slots or anything? maybe an RMA on the ram or mobo?