Need some help finding a PSU with four EPS12V

[CatHerderCam]

OK so, I have been in the prosses of building out a new workstation for one of our devs. Happy me diceded that we were going to go Epyc instead of Xeon. Found some well prices product and off to the races we went.

I picked up a Tyan S8253GM4NE-2T and two Epyc Rome 7282. This was on a from Newegg Combo. Its a E-ATX Board and will fit in the Supermicro 4U/Tower case we already have. Due to the location of the sockets and PCIe I also ordered a compact 3060 for the GPU, as well as 256GB (8x32GB) of DDR4-2933MHz to allow for an dropin upgrade to 512GB in the future.

Here is where the problem comes to play. I got the mobo in and what it failed to yell at me, and I missed in all the research between all the boards, is that this one uses four EPS12V conectors. Haven hunted down the manule (that it did not come with) the discription is as follows:

2.13 Installing the Power Supply
There are Five (5) power connectors on your S8253 motherboard. The S8253 supports EPS 12V power supply.


Thats blew my mind and reads like I do actualy need all four EPS12V, since each socket has seprate ones for PCU and Memory.

SO HERE IS MY PROBLEM
I cant seem to find an PSU with four EPS12V. The only thing I can find is this NZXT PSU which seems to be able to push more eps12V if I use the right cables in the PCIe/CPU ports, but that would only leave me with one PCIe 6+2. So any thoughts or a direction to push me down. I keep getting told to use 2 PSUs for the Mobo by crazies, but that is a non starter.

Thanks in advance for the help.

 

[BlueFox]

Since you presumably have spare PCIe power connectors, why not just get some PCIe to EPS12V adapters?

 

[CatHerderCam]

Since you presumably have spare PCIe power connectors, why not just get some PCIe to EPS12V adapters?

Will that actualy work? I know that the pinout on PCIe is 3 12V pairs and 2 listining pins, and EPS12V is 4 pairs of 12V

 

[BlueFox]

Yeah, it works. PCIe obviously can provide slightly less power than EPS12V, but even with 2 adapters, you're looking at 1100W+ (12V only) being delivered to your motherboard. Hardly a concern with a pair of 120W TDP CPUs.

 

[RolloZ170]

I cant seem to find an PSU with four EPS12V.

Seasonic full modular PSU have both CPU and PCIe output same 8 pin, you can buy additional cables.
corsair modular PSU should work same way.
imho a 3 to 4 pin cable for the memory connectors will be never a problem with actual memory types/sizes.

 

[bayleyw]

Do what @RolloZ170 said, I believe some of the Corsairs have the same feature (PSU end is the same for EPS12V or PCIe).
Also, your memory channels are underpopulated (it doesn't matter for the 7282 which can't take advantage of the bandwidth anyway, but will matter slightly for the larger SKUs). The optimal memory configuration for Epyc is 8 3200MHz DIMMs per socket.

 

[RolloZ170]

of course there are many Gigabyte MSI which have the same because the OEM is Seasonic or the same as for Corsair.

 

[i386]

four EPS12V

I checked the link of the mainboard and I only see two 8pin connectors?
I have some older consumer/prosumer psus from 2014/15 and they have two of those, 1x 8pin and 1x 4pin+4pin (+ additional pcie/gpu connectors)

Edit: I'm blind, two on top and two at the bottom

 

[RolloZ170]

I checked the link of the mainboard and I only see two 8pin connectors?

there are four, use glasses

 

[Spartus]

Dont buy a new PSU, you clearly don't need a lot of power for this build and are just dealing with picky firmware and design of the board.

Just get pcie to EPS cables. They exist because for some reason tesla cards, like A100, use EPS for power, not PCIe. Normally they connect 2 PCIe to 1 EPS to be safe, because EPS carries more current (4 pairs, vs 3 pairs on 8 pin PCIe). If you were powering a tesla you would want this 2 PCIe -> 1 EPS adapter, but you could go 1:1.

Make sure to get the right genders. The opposite cable also exists.

 

[Spartus]

Oh one other trick, most likely each 8 PIN EPS is wired together and not broken out internally as 4 + 4. If you have a lower power build such as yours you can do 4 pin into 8 pin connector and the board wont complain.

thus, If you current 8 pin is actually a 4+4 you can split it, and put 4 into each 8 pin socket, and it will probably run happily that way. Only do this if you know your power draw is < 8 pin limit (which yours comfortably is)

 

[i386]

I cant seem to find an PSU with four EPS12V. The only thing I can find is this NZXT PSU which seems to be able to push more eps12V if I use the right cables in the PCIe/CPU ports, but that would only leave me with one PCIe 6+2. So any thoughts or a direction to push me down. I keep getting told to use 2 PSUs for the Mobo by crazies, but that is a non starter.

Supermicro has this adapter for the threadripper pro mainboard/systems: CBL-PWEX-0663 ($10 at supermicro estore)

 

[CatHerderCam]

Lots going to go on in this post, so sorry for the length

Seasonic full modular PSU have both CPU and PCIe output same 8 pin, you can buy additional cables.
corsair modular PSU should work same way.
imho a 3 to 4 pin cable for the memory connectors will be never a problem with actual memory types/sizes.

That was along the lines of the NZXT ones that I have been buying for our other machines, I did acualy end up finding this about an hour before you posted and picked up a PX-1300w overnight from B&H

Dont buy a new PSU, you clearly don't need a lot of power for this build and are just dealing with picky firmware and design of the board.

Just get pcie to EPS cables. They exist because for some reason tesla cards, like A100, use EPS for power, not PCIe. Normally they connect 2 PCIe to 1 EPS to be safe, because EPS carries more current (4 pairs, vs 3 pairs on 8 pin PCIe). If you were powering a tesla you would want this 2 PCIe -> 1 EPS adapter, but you could go 1:1.

Make sure to get the right genders. The opposite cable also exists.

Thanks for that information, I did end up picking up that Seasonic PSU, the one in the current case is a 650 and turns out it did not have enough conections at all, even with the PCIe 1:1

Supermicro has this adapter for the threadripper pro mainboard/systems: CBL-PWEX-0663 ($10 at supermicro estore)

See I trust Supermicro, I did end up getting a new PSU but its good to know that they are avalible though them.

I checked the link of the mainboard and I only see two 8pin connectors?
I have some older consumer/prosumer psus from 2014/15 and they have two of those, 1x 8pin and 1x 4pin+4pin (+ additional pcie/gpu connectors)

Edit: I'm blind, two on top and two at the bottom

I had the exact same issue looking at the image and did not see the two hiding in the corner untill it came in.


All-in-all thanks you all for the help, my next chalange is going to be getting windows working on it, but that is a problem for next week me xD

 

[i386]

my next chalange is going to be getting windows working on it

If you want to try/use windows 11 get the newest iso. Some older images caused bluescreens/bootloops after installing the amd sp3 drivers on my h12ssl.

 

[CatHerderCam]

If you want to try/use windows 11 get the newest iso. Some older images caused bluescreens/bootloops after installing the amd sp3 drivers on my h12ssl.

Im going to need to get into the bios to see if fTPM is enabled on the board, as the standalone TPM module is not publicly avalible.

 

[Sean Ho]

Just a reminder, apologies if it's obvious to you, but remember the pinouts for PCIe and EPS are exactly opposite; with EPS the 12v are on the side with the clip. If you get a PCIe-to-EPS cable, make sure it's not a straight-through extension cable. Also, pinouts on the PSU side are not standardized, even within the same brand (e.g. EVGA GQ vs EVGA G+).

Do double-check with a multimeter so you don't fry your PSU and/or motherboard!

 

[CatHerderCam]

Just a reminder, apologies if it's obvious to you, but remember the pinouts for PCIe and EPS are exactly opposite; with EPS the 12v are on the side with the clip. If you get a PCIe-to-EPS cable, make sure it's not a straight-through extension cable. Also, pinouts on the PSU side are not standardized, even within the same brand (e.g. EVGA GQ vs EVGA G+).

Do double-check with a multimeter so you don't fry your PSU and/or motherboard!

The PSU we ordered has combo EPS12V/PCIe outs on the PSU itself, and we ordered more of the EPS12V cables to use, so no need to wory about that. That was one of the reasons I was concered about the adapters, espicaly with me seeing that there are Molo to EPS12V(that scares me to no end).

 

[Sean Ho]

I mean, it all can work, just watch the polarity and ampacity of each link in the chain.

Molex 8981 is not an inherently unsafe design (though the pins can get a bit wobbly with loose tolerances). It got a bad reputation due to molded Molex-to-SATA cables, but the problem is not Molex but molded connectors, where the pins are poorly soldered to the wires and wrapped in an opaque plastic housing so you can't tell. Properly crimped connectors or IDC are just fine.

Having said that, Molex only has one 12v/gnd pair, vs four on EPS, so certainly its ampacity is lower.

I'd still use a multimeter to double-check the voltage at the end of the cables, with the PSU powered on using a tester plug (short pin 16 to ground). But I'm sure it'll be fine.