What is the best mining card with hash to power consumption ratio for monero mining as of 2017-10?

Question

I'm looking to get an updated GPU card for mining Monero. I've been reading the new Vega cards are good, but which ones are the best for hashing? I don't need to pay for electricity, so that's something to also consider. My other questions are:

• Can you use 2-4 Vega cards at once?
• How much power does it consume? My breaker pops at 2000 W, btw.
• Which motherboards work with multi card setup?

Answer 1

You might expect some 150w-200w per card plus 300 w from the rest of your PC. For safety, you should try with a larger breaker. 2500 w should be fine.

Edit: there are motherboards designed with several PCIx1 and PCI x16 ports and even several power ports so you can plug up to three Power Supply Units to said motherboard and up to 19 GPUs.

You need to protect this investment. May I suggest buying an additional UPS to protect it from power surges and voltage variations. Also you'll need HVAC equipment. If you're plugging all this from one breaker, you need to consider the higher demands.