Note:  I seem to be unable to provide links to images, website, or product manuals to reference for my question.  The TYAN motherboard manual can be found when googling the board under Docs/FRU.  See pages 14, 15, and 38 specifically.

This is also for a dual EPYC 7773x (280W each) + 2 TB of ram system.
 
I am building on a dual socket EPYC board (TYAN S8253 (S8253GM4NE-2T)) using an EVGA 1600 T2 power supply and it seems to me that the power supply did not come with enough CPU power cables to power the board.  Right now I am using 1x 24 ATX-Pin Cable and 2x EPS/ATX12V 8(4+4)-Pin Cables.  It seems like I need 2 more of the EPS/ATX12V 8(4+4)-Pin cables.  The other, probably more important issue, is that I don’t see any additional CPU Power ports in the back of the power supply if that’s the case.  If I am correct in my assessment, does that mean this power supply is insufficient to power this board?  I find it hard to believe that a 1600W power supply could not be capable of powering this board, so I feel like I must be missing something. 
 
 
Thanks

Edit: updated post for system build details.

PSA adding a photo to your Post - EVGA made some changes - Post Directions below
 
You will need to use a image host site for photos, make sure your settings are for Public viewing of the images

Sajin
Yeah, it can't power the entire board as it doesn't have two additional eps cables to power the other processor/ram. Do you only have one cpu installed on the board at this time? If yes, you might not need the other two eps cables. If you have two processors installed then you definitely need the other two eps cables.

I am running two processors. Both 280W.

I found a splitter cable 1x 8-Pin to 2x 8-Pin of this type, a few listed on Amazon and elsewhere, don’t think I can link them, but not EVGA brand. I recall reading EVGA does not recommend using non-brand cables, that they may even be proprietary, but there is no such cable offered by EVGA. Might any of those work? Can another port be converted into one of these possibly (like a 6+2 PCIE -> CPU 4+4)?

If not, is there any work around besides buying another PSU?

Cool GTX
You will need to use a image host site for photos, make sure your settings are for Public viewing of the images

Hmmm… I tried doing that originally with no luck.

rjohnson11
Dual socket boards are normally workstation business motherboards which 'may' require a different PSU. Remember to read the specs of a PSU before you buy it. I think the Thermaltake TF1 1550 watt has 4 CPU connectors, but you need to recheck the specs:
 

Yea, that’s my mistake. I just assumed 1600W, surely must work. To be fair, I tried looking for alternative PSUs that supported more of these connectors and couldn’t find any, even server class. It’s not like I’m overclocking this, so I don’t think it’ll be drawing more power than other dual socket boards that are for the most part similar to this one but by a different brand. The SuperMicro one only requires 2 cables. I tried contacting TYAN support directly about it.

Thanks for the link!

Personally I don't like PSU splitters regardless of the PSU manufacturer. 

page 38 of the Tyan motherboard manual (HERE) lists that J64/J65 are "memory power connectors". this is pretty unusual, even for server boards, and especially since this board is only 1DPC. I'm willing to bet that you could leave J64/J65 vacant/unplugged without any problem. If you absolutely need them, you could also get a PCIe->EPS12V adapter to use two of the PCIe leads to power these connectors.

Cool GTX
Do you really NEED all (4) 8-Pin CPU sockets to be Populated ?  (2) 8-pin for each CPU  (are you running stock clocks?)

Talked to TYAN support, I do need to power all 5 connectors. I asked them for more specific suggestions, waiting to hear back.

Cool GTX
Is their a designated primary 8-pin for Each CPU ?  You MIGHT be able to run each CPU with just (1) 8-pin

Not entirely sure, but it seems one set is for the CPUs and one set for the memory. (gsrcrxsi beat me to the punch mentioning this)

Cool GTX
if your Going to use a splitter ... buy a quality one .. check with CableMod or some other well known custom wire Mfg

Better Yet - get a Custom cable pinned for  PCIe --> CPU .... Just make sure you mark it & never try to connect a GPU with it

Don’t mind doing that, just not sure how to be super certain it will be compatible.

Cool GTX
Dual CPU - MB need server PSU, that have native support for the extra connections
 
There are "auto switches" to run two PSUs also - in this case the second PSU could be smaller to run 2nd CPU & say all your SATA

I am starting to look into that, but it seems somewhat unnecessary for now, it seems like finding a couple of appropriate cables should make the current solution in place viable.

Cool GTX
suggest you edit your first post & add "for Dual CPU MB" ... that would be much clearer title
EVGA 1600W T2

Done.

I have sent an inquiry out to CableMod.

In the meantime, is there really no stock solution? It seems like this is probably commonly asked for cable for PSUs that contain only 1 connector but need 2, or that a cable like this should already exist by a third party provider that is already deemed compatible.

Updated titles of Post, throughout this thread