What can I upgrade next

[nimonster]

I have:
Z97x killer
i5 4690k stock cooler
Gtx 970
850 evo
8gb ram

What can I do to improve this build?

 

[Calnin]

you have K series cpu. Get a cpu cooler and overclock that thing. Considering you have a 970 and an i5 with a high end board, your PSU should be decent enough to support an overclock.

 

[turbopiki]

Get a CPU cooler an OC the CPU. You could also impove it with PSU if the one you have now or planning to buy is bad quality.

Here you can check which PSU are good quality (Tier 1 or 2) - http://www.tomshardware.co.uk/forum/id-2547993/psu-tier-list.html
You need good quality 500w or more PSU

If you dont have storage drive you can get one.

And the last thing you can improve is Case if the one you have now is a cheap one with low airflow or some problem like that

 

[nimonster]

No I have a storage drive and a 850 watt PSU. What's your opinion on selling the i5 and getting the i7 4790 or 4790k?

 

[synphul]

It depends what you plan to use your system for. In most cases I would say it's a big spend for little performance gains but there would be gains. Again it depends on the tasks you're doing as to whether you'll really see much of those gains or not. An aftermarket cooler would be a good addition regardless if keeping the i5 or upgrading to the i7.