What to upgrade first?

[SirDigby]

Hi guys,
In the coming months is my 18th and I also start my apprenticeship in October, which means I'll finally be earning a steady income. I know I'm definitely going to upgrade by the end of the year but I have a few questions first, but first let me show you my current rig.

CPU: AMD Phenom ii X6 1045T @ 2.7 GHz
MOBO: Asus M5A78L microATX
GPU: AMD Radeon HD 6870
PSU: Colors-IT 550W
RAM: Corsair Vengeance 2*4GB @ 1600MHz

Right, so the issues I'm facing here is whether I should do it all in one go and save up or do it gradually, and if I do either I just want a second opinion on compatibility. So, I was planning on either upgrading to:

CPU: Intel i5-4670K 3.4GHz
MOBO: Gigabyte Z87-HD3
GPU: Nvidia GTX GeForce 780
PSU: Corsair CX750W

So I could either by the CPU, MOBO and PSU together and transfer my old stuff for a few months, or I could get the GPU and use that with my existing rig for a few months.
My questions are:

• Would the GTX 780 work with my current motherboard & power supply?
• What offers the biggest jump in gaming performance?

Thanks guys, it's would be a great help! The upgrade should cost me about £630 in total, I'm not sure how much I'll get for my 18th, and if I do whether I want to burn through it all right away so I'd rather do it in £300 or so chunks which conveniently it splits up into (£300 for CPU, PSU & MOBO and then £330 for GPU).

 

[St1ckM4n]

The GPU offers biggest jump in gaming performance, but it recommends a 600W PSU. Considering you have an old Athlon 6-core CPU that chews power, and an old no-name PSU, I wouldn't risk it.

 

[SirDigby]

Ok,so I'll get the PSU, MOBO and CPU first, should I get them all in one or get the PSU and wait for the other 2?

 

[St1ckM4n]

PSU first, because there were a couple new features with Haswell regarding power efficiency. Make sure you get Haswell-compatible PSU.

@GhostRyder or JC could help you wth this, they're knowledgeable dudes.

 

[SirDigby]

PSU first, because there were a couple new features with Haswell regarding power efficiency. Make sure you get Haswell-compatible PSU.

That Corsair CX750 should be up to it, it says it's Haswell compatible, it's a trusted brand, high power output and reasonable price. Looks like I'm good to go - all I need to do now is acquire the money!

 

[hopgop1]

You can do what you like it's your money and your PC, but the prices are only going down and I would wait until you can afford the rest then buy to save a little money.

 

[SirDigby]

You can do what you like it's your money and your PC, but the prices are only going down and I would wait until you can afford the rest then buy to save a little money.

I'm not asking permission, I'm asking for advice on compatibility and performance jumps.

 

[hopgop1]

I wasn't saying that I was saying that the longer you wait the further prices will go down and the more performance you can get for your money.