f you're going to benefit from the HT offered with the 4790k, then go ahead. If you're purely gaming and not going to utilise the extra threads, hold on to the 2500k. Keep in mind that a CPU upgrade to a 4690k or 4790k will warrant your motherboard useless and you will require a motherboard upgrade as well. You may also be better off upgrading PSU and/or case. Adding an SSD would be beneficial if you don't already have one. If you could list all of your current specs, including PSU, make and model and your full upgrade budget, then this would be much easier.

Craigyy_JR wrote f you're going to benefit from the HT offered with the 4790k, then go ahead. If you're purely gaming and not going to utilise the extra threads, hold on to the 2500k. Keep in mind that a CPU upgrade to a 4690k or 4790k will warrant your motherboard useless and you will require a motherboard upgrade as well. You may also be better off upgrading PSU and/or case. Adding an SSD would be beneficial if you don't already have one. If you could list all of your current specs, including PSU, make and model and your full upgrade budget, then this would be much easier.

Leaving for work or else I could.