FPS lag with new graphics card on minecraft?

I'm getting 40-50 fps on minecraft even tho i've gotten a new MSI R9 270 graphics card.
It has all the newest drivers and such and i have no clue why it does that.

any suggestions?

thanks for all responses.

Added (1). My pc specs are:
CPU: Intel i3-2120 3.3GHz
PSU: Corsair CX430W
GPU: MSI Radeon R9 270
MOTHERBOARD: GA-H61M-S1 rev 2.1
MONITOR: Philips 1080p 226V
TOSHIBA 500GB HDD
RAM: 8 GB ( 2 x 4gb ) crucial ballistic sport
OS: Windows 7 Home premium 64-bit

Guest

Hmm your computer specs seem ok to me, maybe its because the graphics card you bought dosent match your Input? I'm not entirely sure try taking some stuff of like 'clouds, high particles' and things which take up fps it should improve.

keelan

Issues:
1) Your power supply is too small. Minimum recommended is 450W, and that means a good name brand, single rail +12V design. Usually one would get a 500-600W PSU with that video card.
2) i3 - not the best for CPU intensive games like Minecraft, CPU will be very busy. Even then, make sure Minecraft has definitions set to use multi-CPU cores if you have not done so already. (set to use 2 cores instead of default one core)

Adrian