Hi Calum, like Joe says, the graphics card is not the best for FSX, but that processor is definitely not going to help. I use an NVidia GTX 760 SC along with a Core i7 3770K processor overclocked to 4.4Ghz and get superb performance wherever and whatever I am flying. Pound for pound, the Core i7 series are by far the best for Flight Sim, preferably 4.0 Ghz plus, either native or overclocked. Unfortunately that would also require a motherboard change as well. NVidia Inspector is a free tool that will let you tweak settings on the card and save them as profiles for any software you like.
Also I have to agree with Joe about Steve's DX10 Fixer. This is, without doubt, the best performance enhancing tool for FSX ever made, and it also allows DX10 features such as dynamic lighting, texturing and all kinds of effects that old DX9 just isn't capable of. At £19.99 it's an absolute steal! Again, this works best with NVidia cards, although there are setup options in the manual for AMD users.
Well worth saving up for IMHO!!