Hello,
 
I am building a 10 GPU Titan V rig. Can someone tell me whats the minimum power suppply I should be using? thanks! 

Sajin joke, I don't know what you have from system but I would not go below EVGA 850 P2.
Minimum is 750W for freedom with all processors and overclocking. 
 
Example owners of Z370 Micro and i7-8700K could use even EVGA 650 P2.
Same as previous models of Intel Z chipset and i7 K processors.

What will this system be used for? That may help determine what power supplies you need. 

You should use a server power supply that is rated for a server with 10 gpu’s.

This kind of rig will need one, if not two, dedicated 30AMP circuits. Each 1600W PSU needs a dedicated 15AMP circuit. You can put two on a 30AMP, but that would have to be through a UPS with the correct NEMA plug configuration (usually 4 prong like your clothes dryer), as well as enough watts to handle the two PSUs. You will need 2,500W of PSU power just for the GPUs but will also need one with a rail large enough to handle a number of them, since not all PSUs have one rail that can handle this much power since not all wattage available is on that rail. I would recommend using 3 PSUs for this project in a circuit that can handle at least 3,000W given the motherboard and CPU to power this system along with a (or a number of circuits that equal) 45AMP or even 60AMP. 3,000W with only 3,200W of power is too close for my comfort, this is even before I look at my electrical panel and call someone in to bring the appropriate circuits to the area I want this to be working in. Once you do, you may need more service brought into your home or office, as you may not have enough AMPs available in the current set up. Good luck, as this is not a simple question. The GPUs are $30,000+, but I would expect few additional thousand (minimally) for just the electrical upgrades, as the UPS is very expensive at this size too. This is a $50,000 project with everything included. If this is for mining, then the return will be many years after the costs of electricity to make this all work. Wait until you get the electric bill each month.

ty_ger07

Vlada011
Sajin joke, I don't know what you have from system but I would not go below EVGA 850 P2.
Minimum is 750W for freedom with all processors and overclocking. 
 
Example owners of Z370 Micro and i7-8700K could use even EVGA 650 P2.
Same as previous models of Intel Z chipset and i7 K processors.

750 watts minimum for ten video cards? You will need MUCH more than that. I think that you misread the user's needs.

WHAT 10x 3000$ WORTH GPU, 30.000$.
That 2x1600W... For what 10 TITAN V?
Minining? 
 
In Europe would be much easier and far better.
2x EVGA 2200 W. Every PSU for x5 GPU on different power jack in wall.
 

BTW, I think its a total misconception that you need to have a coin that you mine explode or take years to recoup investment. Accumulate over time and i think you would be surprised what some of these projects will do and the returns you get.