Since switching to the AMD R9 290X, I've had terrible performance compared to my old GTX 570. Whereas the GTX 570 will run at 300fps, a significantly faster card is getting only 90fps. That's just the tip of the iceberg.
Setting the render distance anything above 16 chunks in 14w33a has caused this to happen:
Setting the render distance anything above 16 chunks in 14w33a has caused this to happen:
http://imgur.com/a/0M4I0
I've switched between Java 7 and Java 8, all 64 bit versions. No difference
I've allocated more RAM. No difference
I'm on AMD drivers: 14.20.1004-140811a-174673E
And have an i5-3570K currently clocked at 3.4GHz (stock)