Using two powersupplies on a single motherboard / powersupply bridge

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coffeeprogrammer

Well-known member
Jul 19, 2021
198
20
I recently bought a Telsa p100 video card which is common in data centers, the problem is that my power supply does not seem to supply enough power to power up when it is supplied. I asked gemini if it is possible to use two power supplies on a single system and it recommend a power supply bridge which I found and order on amazon along with another power supply. Has anyone ever used one of these? I just looks like it is a Y adapter for the 24 pins that plugs into the motherboard.

 
Google says the power requirements are 250W https://www.leadtek.com/eng/products/ai_hpc(37)/tesla_p100(761)/detail but it's my experience that nVidia GPUs can peak well over their rated spec. You should really have a good single powerful PSU, at least 850W, and note that you should be taking the two feeds for the GPU from TWO DIFFERENT CONNECTORS back to the PSU. (Some PSU connectors have multiple heads, you should definitely NOT use more than one of such connector.)
 
I recently bought a Telsa p100 video card which is common in data centers, the problem is that my power supply does not seem to supply enough power to power up when it is supplied. I asked gemini if it is possible to use two power supplies on a single system and it recommend a power supply bridge which I found and order on amazon along with another power supply. Has anyone ever used one of these? I just looks like it is a Y adapter for the 24 pins that plugs into the motherboard.

That connector looks to me like it is a 1-2 not a 2-1. In other words it is to supply two motherboards from a single power supply. Look at the ends carefully, there are two plugs ( motherboard end) and one socket (PSU end).
 
I think you are right, but I found a different cable that I think is right:



I also seen some linus tech tips, where people were asking about using two power supplies on one computer, I think what it is doing is just doubling the lines from the motherboard telling the power supply to turn on, so in the photos, you only see two wires going to the 24 pin interface of the second supply.

I also am quite sure my problem is that the power supply it too weak, if I connect two nvidia 1070s or one tesla p100 to only the power and not the pci bus, it still will not power on. If I connect the tesla p100 but not the extra power supply it starts on and I can see post text, but it ends up in a reboot loop never getting to the OS.

I looked like people that build those mining computers sometimes use multiple power supplies.
 
I recently bought a Telsa p100 video card which is common in data centers, the problem is that my power supply does not seem to supply enough power to power up when it is supplied. I asked gemini if it is possible to use two power supplies on a single system and it recommend a power supply bridge which I found and order on amazon along with another power supply. Has anyone ever used one of these? I just looks like it is a Y adapter for the 24 pins that plugs into the motherboard.

The connector that tells the second psu to power up works. However, all psu will have small differences in voltages. This will cause a small current to flow between wiring connecting both voltages. Thus heating the voltages. Since the currents in computers can be very large (10-100A), this could represent a lot of heating power.

I use this in a computer I have, but have segregated the power so that each device (gpu, hd, mb, etc) only uses that from one of the psu. The signal lines don't really matter, since the inputs are usually high impedance. All the grounds should be interconnected

Corsair HX1200i
├── Current uptime 20:38:40
├── Total uptime 1572 days, 15:38:40
├── VRM temperature 47.5 °C
├── Case temperature 37.2 °C
├── Fan control mode Hardware
├── Fan speed 0 rpm
├── Input voltage 230.00 V
├── +12V OCP mode Multi rail
├── +12V output voltage 12.11 V
├── +12V output current 32.75 A
├── +12V output power 398.00 W
├── +5V output voltage 5.05 V
├── +5V output current 1.06 A
├── +5V output power 5.00 W
├── +3.3V output voltage 3.30 V
├── +3.3V output current 1.88 A
├── +3.3V output power 6.00 W
├── Total power output 406.00 W
├── Estimated input power 433.00 W
└── Estimated efficiency 94 %

Corsair HX750i
├── Current uptime 20:13:56
├── Total uptime 1118 days, 10:13:56
├── VRM temperature 43.8 °C
├── Case temperature 28.8 °C
├── Fan control mode Hardware
├── Fan speed 580 rpm
├── Input voltage 230.00 V
├── +12V OCP mode Multi rail
├── +12V output voltage 12.14 V
├── +12V output current 36.25 A
├── +12V output power 440.00 W
├── +5V output voltage 4.94 V
├── +5V output current 3.38 A
├── +5V output power 16.50 W
├── +3.3V output voltage 3.33 V
├── +3.3V output current 2.06 A
├── +3.3V output power 6.50 W
├── Total power output 464.00 W
├── Estimated input power 501.00 W
└── Estimated efficiency 93 %