You can use a second psu if your first one is out of connectors...or near its limit on total power...but you need to follow a few basic rules for dual psu.... (atx psus...likewhat you are using now)
You can use a 2pin y cable that will start both psus at same time. like this... https://www.amazon.com/Qaoquda-Power-Supply-Adapter-Motherboard/dp/B078W4H16S/ref=sr_1_1?dchild=1&keywords=dual+psu+y+cable&qid=1610902119&sr=8-1
You must connect all mobo connections to one psu... (cpu / molex )
Each gpu & riser must be from the same psu. Never gpu from psu 1 and riser its on connected to psu 2....that is a nono.
Thats pretty much it.
You can also do it with your psu (again only it hooked to motherboard)
Then power gpus/riser combos until the psu1 is full. Again never combine psus to a gpu/riser combo.
Then for second psu you can use something like a server psu with a break out board....
https://www.amazon.com/579229-001-Platinum-Supply-Certified-Refurbished/dp/B07HFJHFZ9/ref=sr_1_1?crid=16DALFEDVT53F&dchild=1&keywords=1200w+server+power+supply&qid=1610902320&sprefix=server+1200w%2Caps%2C190&sr=8-1
with an adapter like
https://www.amazon.com/Ethereum-Mining-Breakout-Adapter-Graphics/dp/B07D6NC5LK/ref=sr_1_2?crid=3CKPJ9BQNK1EQ&dchild=1&keywords=server+psu+breakout+board&qid=1610902366&sprefix=server+psu+brea%2Caps%2C199&sr=8-2
And you will have a lot of 6 and 6+2 connectors and 1200ws added to your rig.
Current rig has 2 corsair PSU using the 2 pin Y cable as you posted earlier.
main PSU that is 850 W is powering the Mobo and 3 GPUs and their risers. Other CPU that is 1000W is powering remaining 4 GPU and its risers.
I want to replace the SATA cables with the PCIE cables.
So both PSU would have 4 6-Pin and 1 8-Pin slots available at back.
Ideally if I could find a wire with 6-Pin at one end and PCIE at the other end it would be great.
I want to avoid using server PSU as they are noisy.
Thanks a lot for your help.
Well the other option is the TRIPLE PSU adapter....work just like the 2....same rules apply....only a single psu for mobo or any gpu/riser. As the movie lines go....”Do not crosee the streams!”
https://www.amazon.com/Ports-Triple-Supply-Motherboard-Adapter/dp/B07CMK58RD/ref=sr_1_1?dchild=1&keywords=triple+psu+y+cable&qid=1610906010&sr=8-1
Im not sure how loud you think server psus are...they are a bit louder due to smaller size fan. They make a bit more noise but as ypu look at 3 psus their fans usually arent silent either..and i can tell you on big rigs with 13 cards the gpu fans make more noise thean anything else....26-39 fans buzzing away makes some noise. The server psu is the least expensive way to add a lot of power which is why a lot of folks use them. Currently PSU prices are like gpu prices...silly.