Could someone confirm my GPU wiring please

[MadeIt]

Hi all,


I have a GPU rig that isnt quite booting correctly and am wondering if someone might notice something obvious im doing wrong...

Rig:
Mobo - Asrock H81 Pro BTC
CPU - Intel Celeron usual thing
Ram - 4GB HyperFury
SSD - 32GB USB
OS - EthOS
PSU - (PSU1 EVGA 650 GS) and (PSU2 EVGA 650 G2)
Risers - Usual 1x-16x powered
GPU - 4no. Sapphire RX470 OC Reference

(PSU1 is always powering the mobo)


I can get the rig to boot with 1no. GPU plugged into PSU 1 (both riser power and card power) and with 2no. GPU plugged into PSU 1 (both riser power and card power).
If I plug more than two GPUs in, then the PSU clicks (presumably an overcurrent protection of some kind) and the rig wont boot.


(I can repeat this two gpu set up with PSU2 as well as proof that the second PSU is working)


I then try to power the other two cards with the second PSU..

I have tried booting with PSU1 taking the mobo and 2no. GPUs (riser and card power) and with PSU2 taking 2no. GPUs (riser and card power) I then bridge the pins on the 24pin connector of PSU2 and power it on just before powering on PSU1 (i have also tried powering it on just after powering on PSU1 to the same effect)
This either doesnt boot anything at all and both the PSUs click (the presumed overcurrent protect?) Or PSU1 boots and PSU2 stays off...

I then tried plugging all four GPU riser card powers into PSU1 (along with the mobo) and the card main power into PSU2 but this does the same PSU click and nothing...


In my process of debugging.. I also discovered that plugging PSU1 with the mobo and 2no. GPUs would only boot when the riser board power cable adapters were plugged in???
So the riser boards have molex plugs and then molex-to-sata adapters... the rig will boot IF the molex-to-sata adapters are plugged inbetween the riser board and the PSU, but if i remove the adapters and just plug the riser boards in directly to molex cables from the PSU then i get the same PSU click and no-start..



Please see this image for clarity

https://pbs.twimg.com/media/DGp9vOHWAAAwqHA.jpg

Blue lines are power lines to the PCIe riser boards and pink lines are main power to the GPUs
Is option A or B correct? Or is there another option..?


Oo... furthermore, I tried to plug in some Sapphire Nitro+ RX570 4GB cards that I have on another rig and they work just fine, except when I try to run one RX570 and one RX470.. in which case it doesnt boot...


I hope this all makes some semblance of sense.. I have been trying a million different wiring configurations and spend hours plugging and unplugging to no avail!
What am i missing! haha

Much appreciated

[1714170843]

1714170843

[1714170843]

1714170843

[1714170843]

1714170843

[Undefined31415]

Use molex to SATA adapters at your own risk. SATA power connectors were not designed to handle the current that a graphics card might draw through the x16 slot (and in your case, the riser power adapter). You'll *probably* be okay if you distribute them such that one PSU line of SATA connectors only powers one riser, and avoid using all available connectors on the line for risers.

Powered risers with 6 pin PCIe power connections are better, but your risers that take molex connectors should be fine if you power them from molex connectors, and not with SATA power via an adapter.

I would try using PSU2 for the motherboard/CPU/drive. EVGA PSUs are generally good, but the lower-end (650/550) G2s are often better than their GS counterparts (both supplies are still manufactured by Seasonic, iirc), and I'd try keeping the better of the two as the primary PSU. This shouldn't matter if both PSUs are working as intended, but it's an idiosyncrasy of mine.

For a dual PSU setup that you're doing manually (without some special cable or fancy ADD2PSU), you need to have the pins (green to any ground on the main 20/24 pin connector) shorted on the secondary PSU prior to booting up the system. Don't try timing it to turn on the second PSU immediately after; there's no need.

With that motherboard, you should not need to use the motherboard's molex connections if you are using powered risers.


How many cards (and which) are you planning on running on this rig? You initially mentioned that you have 4x RX 470 cards, but your diagram shows 6 cards, and later you mentioned having RX 570s, so I'd just like to know what your goal is for this rig.

I haven't thoroughly checked what connectors your PSUs should have available, so let us know if there's any kind of limitation there.

[fanatic26]

It sounds like you have a bad PSU. A 650w PSU functioning normally can run 2 of your video cards with no problems. It sounds like there is either a short in one of the video cards causing it to fail or the PSU itself is the problem.

Also, the Molex to Sata 'problems' that people on this forum warn about are non existent. As long as you only plug in 2 risers per chain on the PSU you will be fine. They wont burn up unless you overload the 12v wire powering the chain of SATA plugs. I have literally THOUSANDS of molex to sata connectors powering graphics cards without ever once having a single failure on the adapter line.

[bmartin44]

Besides powering issue, I also curious to know if option A that connect GPU with it's riser on same PSU is the correct one, or option B that connect all risers with PSU that connected to motherboard? Thanks!

[Regulater]

Hi all,


I have a GPU rig that isnt quite booting correctly and am wondering if someone might notice something obvious im doing wrong...

Rig:
Mobo - Asrock H81 Pro BTC
CPU - Intel Celeron usual thing
Ram - 4GB HyperFury
SSD - 32GB USB
OS - EthOS
PSU - (PSU1 EVGA 650 GS) and (PSU2 EVGA 650 G2)
Risers - Usual 1x-16x powered
GPU - 4no. Sapphire RX470 OC Reference

(PSU1 is always powering the mobo)


I can get the rig to boot with 1no. GPU plugged into PSU 1 (both riser power and card power) and with 2no. GPU plugged into PSU 1 (both riser power and card power).
If I plug more than two GPUs in, then the PSU clicks (presumably an overcurrent protection of some kind) and the rig wont boot.


(I can repeat this two gpu set up with PSU2 as well as proof that the second PSU is working)


I then try to power the other two cards with the second PSU..

I have tried booting with PSU1 taking the mobo and 2no. GPUs (riser and card power) and with PSU2 taking 2no. GPUs (riser and card power) I then bridge the pins on the 24pin connector of PSU2 and power it on just before powering on PSU1 (i have also tried powering it on just after powering on PSU1 to the same effect)
This either doesnt boot anything at all and both the PSUs click (the presumed overcurrent protect?) Or PSU1 boots and PSU2 stays off...

I then tried plugging all four GPU riser card powers into PSU1 (along with the mobo) and the card main power into PSU2 but this does the same PSU click and nothing...


In my process of debugging.. I also discovered that plugging PSU1 with the mobo and 2no. GPUs would only boot when the riser board power cable adapters were plugged in???
So the riser boards have molex plugs and then molex-to-sata adapters... the rig will boot IF the molex-to-sata adapters are plugged inbetween the riser board and the PSU, but if i remove the adapters and just plug the riser boards in directly to molex cables from the PSU then i get the same PSU click and no-start..



Please see this image for clarity



Blue lines are power lines to the PCIe riser boards and pink lines are main power to the GPUs
Is option A or B correct? Or is there another option..?


Oo... furthermore, I tried to plug in some Sapphire Nitro+ RX570 4GB cards that I have on another rig and they work just fine, except when I try to run one RX570 and one RX470.. in which case it doesnt boot...


I hope this all makes some semblance of sense.. I have been trying a million different wiring configurations and spend hours plugging and unplugging to no avail!
What am i missing! haha

Much appreciated

Are you not using a dual PSU setup? Sounds like it could be an issue with a PSU or when your booting up the system. Recommended to get a dual psu cable then use a Surge protector to turn on and off the units to allow them to start at the same time. Image A would be the setup you would want to use not B.

[MadeIt]

I would try using PSU2 for the motherboard/CPU/drive. EVGA PSUs are generally good, but the lower-end (650/550) G2s are often better than their GS counterparts (both supplies are still manufactured by Seasonic, iirc), and I'd try keeping the better of the two as the primary PSU. This shouldn't matter if both PSUs are working as intended, but it's an idiosyncrasy of mine.

For a dual PSU setup that you're doing manually (without some special cable or fancy ADD2PSU), you need to have the pins (green to any ground on the main 20/24 pin connector) shorted on the secondary PSU prior to booting up the system. Don't try timing it to turn on the second PSU immediately after; there's no need.

Thankyou, I will make sure that the G2 PSU is set to be PSU1 - I shall continue to short the green/black pins prior to boot attempt


How many cards (and which) are you planning on running on this rig? You initially mentioned that you have 4x RX 470 cards, but your diagram shows 6 cards, and later you mentioned having RX 570s, so I'd just like to know what your goal is for this rig.

I have four RX470s (sold two) and two RX570s (four on pre-order...still). I plan on eventually running the four RX470s on my other mobo which is an Asrock H81 BTC (non-Pro) and then running the six RX570s on the H81 Pro BTC. For now though, im just trying to get as many cards online as possible, but am faced with the dual psu issue

I haven't thoroughly checked what connectors your PSUs should have available, so let us know if there's any kind of limitation there.

There doesnt seem to be any limitations with the connectors - they come with quite a fair few and so I havent had any issues except for having to use the SATA to MOLEX adaptors in order to boot...

It sounds like you have a bad PSU. A 650w PSU functioning normally can run 2 of your video cards with no problems. It sounds like there is either a short in one of the video cards causing it to fail or the PSU itself is the problem.

Both PSUs run two GPUs and the mobo just fine on their own.. its only getting them both to boot at the same time with four cards plugged in.. one of the PSUs will then invariably click and not boot...

Also, the Molex to Sata 'problems' that people on this forum warn about are non existent. As long as you only plug in 2 risers per chain on the PSU you will be fine. They wont burn up unless you overload the 12v wire powering the chain of SATA plugs. I have literally THOUSANDS of molex to sata connectors powering graphics cards without ever once having a single failure on the adapter line.

That is very good to hear.. I have noticed that the adaptor at the point it changes from male to female SATA gets warm to the touch. I have been checking this temp and it has been running stable for the last few days. Its odd that the PSU clicks and fails to boot when the adaptors are not plugged in? Could the adaptors be acting as a very small resistor (hence their warmth) and giving the PSU a bit of slack upon boot up?