I was thinking of buying a new i5 3570k or 4670k to oc with a new cooling system. Should I also buy a new motherboard? I also want to upgrade my harddisk and buy a new ssd because it is very slow. Or should i just save up for a new rig? Thanks in advance.
You should also buy a mobo to do overclocking as your current one does not support but the best idea would to build a new system by taking the gpu, ram and hard drive and power supply if sufficient from current one and sell all the parts off.
If you're looking to upgrade to an i5-3570k, or 4670k, you will definitely need a new motherboard (Z87 for overclocking). Your current board isn't compatible with either i5s that you wish to upgrade to. If you do choose to go with either 3570k/4670k, you will notice a decent performance boost. I would suggest going with a SSD as well, speeds up loading times by a significant amount.