Hey @Rufus, Congrats on your 1st Mining Rig.
Based on my own experience the short answer is No… a single PSU will not be enough to get everything. I mine with 6 x RX580’s all of which are only connected individually with a single 8 pin power connector.
Each Card consumes around 130 watts, the Mainboard runs at around 300 watts BEFORE the GPU’s are powered up…all in when running overclocked GPU with minimal power power settings ( i run at -87 on Afterburner per GPU ) my rig runs at 1100 watts.
Now thats below your 1600 but you should never run at full capacity… somewhere around 70% is where you want to be.
Next issue… Its very unlikely that a single PSU will have enough connectors to power everything… You will need the following
1 x MainBoard
1 x CPU
6 x SATA Connectors for the PICI Expansion boards ( no idea why you have not been told to use them, mine runs fine )
6 x 8 pin GPU Power connectors
depending on the MB you may need to power the PCi slots, i run an Asus H110 BM and that needs two MOLEX connectors to power all the PCIe slots. I don’t use them all but the board will not boot without them
Are you running any additional fans, your going to need more Molex connectors for those too
I personally run 2 x 8000 watts PSU, 1 run the main board and 2 x GPU’s the other run 4 x GPU’s
If you do decide to run 2 x PSU’s you will need a multi PSU Controller… this switches the second PSU on when the first is powered up… this controller board also need its own Molex power connector.
Hope thats helps, good luck… its true what they say…getting 6 cards to run all is a bea-atch…