Odd fps with new parts

I got a new GPU and PSU for my computer, i put them in and it all seems to be working fine (had a little fuss with the GPU but it seems ok now) and im having some odd fps drops/low fps. For example on League of legends my old GTX 550 TI stayed around 60 fps constantly, but my new card is just under that, and it varies quite a lot. and i tried to run a modded minecraft (beacuse it has an fps counter) and i found that i would get a constant 40-60fps (which is still quite low for what im expecting on a 1080p setup) but i would often get fps spikes where it would drop to around 20fps, i looked at my cpu utilisation in the task manager, its usually at around 20%, but when the fps drops, it spikes to around 40% then goes back to normal. I have no idea whats wrong, but my cpu is water cooled and it is quite loud, could there be a problem there? any help is apreciated, here are the rest of my specs:

CPU: AMD 8150 FX bulldozer at 3.60Ghz

GPU: AMD R9 270X 4GB OC

RAM: 8GB kingston hyper-X blue 1600Mhz (2x)

1TB HDD

128GB SSD

PSU: 650W OCZ ZS series

CPU cooler: Coolit eco II fat boy liquid cooler

Minecraft is almost all about the CPU and the engine only runs on one core by default. There is a modification called Optifine that makes all the difference, but it might not be out for the current version of Minecraft. Check it out.

did you uninstall the drivers for the last video card?

yes i uninstalled them via device manager

Have you checked the temps while running any games, being you stated the cooler to be loud... I do know the higher end amd cpu's do run extremely hot, i think yours is 130ish tdp so not too crazy but hot none the less. If it is running very hot it could be throttling, also check the temps of your card too, it could be a factory defect and is running very hot too.

That 270x 4G OC is weird, I have never seen one, but anyway, there are multiple reasons why this is happening and i think its probably the PSU or MB. Maybe even heat problems. Check all of those parts and make sure your GPU stays under 90 degrees under full load and your CPU stays under 80 degrees.

ive tried a bunch of games on very high settings, assassins creed 4, skyrim etc. CPU temp never over 50 and GPU never over 60, my cpu watercooler is still very loud though

Also, maybe just try looking at mobo temps as i've had mobo's get hot and do some really weird things too

try this one instead

http://forums.guru3d.com/showthread.php?t=379505