(the fan is not an original; it is a repair,)
to one of these. Radeon R7 260
I have a upper limit GBP100 and wattage 150.
Best price so far fromDabs £92.00 http://www.dabs.com/products/xfx-amd-radeon-r7-260x-2gb-pci-express-3-0-hdmi-92ZR.html#
overclockers.net £99.59 delivered http://www.overclockers.co.uk/showproduct.php?prodid=GX-228-MS
Amazon for £103.94
But I've just come aware of a lower power card (wattage) with more poke for a little bit more bucks.
The GeForce 750 TI. Dabs £97.96
It appears that some GPU heavy apps need some help if you are wanting CUDA support it might be possible to separately download/install from NVidia : https://developer.nvidia.com/cuda-toolkit-31-downloads And to ensure that each app is not using default settings for H/W acceleration. Always tweak if in doubt.