Well it seems you need a GPU update..
Its a shame you've not got a better motherboard because id suggest overclocking the CPU and getting a 7950/7970/280X..
I wouldn't on the motherboard you have though, as it's not very well power regulated.
What is the PSU, if it's a cheap 'no brand' PSU you need to get rid and get a decent one..
For the GPU, id suggest a 7950..
But you need both a new PSU (depending on what it is) and a new GPU.