mining 4x gtx970, how many watts power supply?

i have 4 gtx 970's that i don't use anymore/got given

i might as well do something with them, my friend told me to mine with them,

my motherboard can support it, but not my psu, i only have a 500w,

how many watts psu do i need for 4x gtx 970?

I'd say 1000W is more than enough, but pair them with the lowest TDP CPU you can find and buy the PSU from a reputable brand

At least a 750. https://outervision.com/power-supply-calculator

And apparently, running this 24/7 will cost you over $500/month. LOL!

I'd buy an 850 watter.

3 970's require an 850 watt unit. So if you have 4, get a 1000 watt unit and call it a day.

http://www.realhardtechx.com/index_archivos/Page362.htm

Looks like about $9.50/day revenue. Each card has a 150W TDP, so if you're only running those 4 cards off the PSU, a 750W should be fine. I highly recommend either the eVGA 750W G3 or the eVGA 850W GQ--the 850 GQ is especially nice as it has 4 GPU cables with 2x8pin connectors on the end. This is perfect so you can power the riser and the card off of one cable if the card only requires a single 8 pin connector. If it has an 8+6, then things get a bit more complicated.

https://www.amazon.com/EVGA-Modular...F8&qid=1517015419&sr=8-1&keywords=evga+850+gq
https://www.nicehash.com/profitability-calculator/nvidia-gtx-970?e=0.1&currency=USD