In my laptop (with a geforce) I can get up to 100+ FPS, but with my new desktop ATI r9 280x I can get 30-40 FPS without v-sync (I should get 500FPS).
This problems is worst with minecraft 1.7.10 (30 FPS top).
Lot of people have this problem, I can find lots of forums and YouTube video exposing this issue like:
https://www.youtube.com/watch?v=hcY4v4K61oM

My PC:
AMD FX-8350, 8 cores at 4Ghz
16 Gb ram 1600Mhz
Ati R9 280x
SSD 500gb samsung

dxdiag atached.