fx 6300 with a R9 380/390 ?

Solution
Side grade at best mate - not worth it.

In all honesty anything less than a 290/390 or gtx 970 isn't really going to impress you immensely - the 270x is still a very decent midrange card.

Dunlop0078

Titan
Ambassador
Can it handle it? Yes of course. Will it bottleneck slightly in some games? Yes especially with a 390, every game will still be perfectly playable but your cpu might hold back your gpu just a bit in some games. Are you looking to build a new computer or are you looking to upgrade an old one with a 6300? If you are looking to build a new one post your budget and I might be able to help you out.