Hi I have an I5 4670k and GTX 750ti with a z97 motherboard. What PSU wattage should I get for moderate to somewhat high overclocking for both the CPU and GPU? and what is a good brand?
500W is always a decent starting point if you are going to overclock a CPU and single graphics card. Also make sure you are getting at least an 80 Plus Bronze PSU.
The 750TI is such low wattage that you could probably do fine with a CX430/M but a 500W to 600W would be recommended for future upgrades.
400W will be enough for this system, but 500W is generally optimal for single-GPU systems (you will probably want to upgrade that 750 in foreseeable future).
From what I've experienced with my i5 4670k - it consumes a rough estimate of 85.2 watts while overclocked @ 4.4ghz with 1.32v on the CPU voltage at full load, and roughly around 37 to 64 watts @ stock speeds while at full load. The GTX 750 Ti on the other hand requires 20 amps on the +12v rail and a minimum of 400 watts on the PSU and consumes roughly 60 watts. I recommend that you buy an 80+ certified PSU with an amperage of 30 or more on its +12v rail in order to power beefier GPUs, and with 750 watts - just for the sake of headroom and less heat output if you're planning to overclock. Cooler Master, Corsair and Seasonic has one of the best PSUs and usually - at the right price.
http://forum-en.msi.com/faq/article/power-requirements-for-graphics-cards
decent 500W is enough for any single gpu setup.
even highend cards like a R9-290, GTX970 and what not.
I would agree with 500watts is fine for your current setup, unless u plan on upgrading to 960 or higher, and adding water cooling and hard drives and such. Then you might need at least a 750 watt to future proof yourself.