Precision 3930 Rack: Set up non-redundant power supply

Question

Hi,

I have a Precision 3930 Rack running Windows 10 Pro for workstations (4 cores plus). When I customized it, I only selected to fill 1 of the two power supply slots. I'm planning to upgrade my graphics card, and I will need more power to accommodate. I think I will very quickly be able to install the second power supply unit once I get it, but I do not know how to change the system to non-redundant power. I believe redundant is the default. I have built this configuration online to be sure it is possible.

Inside:

Intel Xeon E-2146G,(6 Core HT, 12MB Cache, 3.5GHz, 4.5Ghz Turbo)

16GB, 1x16GB, DDR4, 2666MHz, ECC Memory

M.2 256GB SED OPAL PCIe NVMe Class 40 Solid State Drive (Boot Drive)

3.5" 2TB 7200rpm SATA Hard Disk Drive

Single 550-Watt Power Supply

Old Graphics Card

Radeon Pro WX 4100, 4GB, 4 mDP to DP adapter

New Graphics Card

NVIDIA RTX 2080 super

Thanks

Useful Links:

<ADMIN NOTE: Broken link has been removed from this post by Dell>

https://www.dell.com/support/manuals/us/en/04/precision-3930r-workstation/precision3930_rack_setup_and_specs/power-management?guid=guid-855f4eb4-acb0-4bbf-b1db-5570cf14df0b&lang=en-us

https://www.dell.com/support/manuals/us/en/04/precision-3930r-workstation/precision3930_rack_setup_and_specs/video-card?guid=guid-a386502e-c899-4399-9aaa-42ee0251b0b8&lang=en-us

Sullen Saucier · Accepted Answer

Solution!

I added the second internal power supply and was unable to boot my system while connected to my new GPU as stated before. I recently purchased the Dell GPU power cable as a last-ditch effort. When I used Dell's GPU power cable my system booted up with no issues. I'm not 100% certain my system is utilizing non-redundant power, as my GPU (RTX 3070 FE) is stated to require a 650w PSU according to Nvidia, but 550w from other sources. Regardless, it works.

On a performance note, my GPU averaged 200 FPS ( +30 FPS compared to when it was on the external PSU) on the NOVA Benchmark.

JoeParker · Answer

I have a similar situation. I want to install an NVIDIA Quadro RTX6000, but my Precision 3930 currently only has one 550W PSU. Any luck on setting up the non-redundant power supply?

Sullen Saucier · Answer

No luck at all. I've been trying everything I can find. I've even tried to set up an external PSU for the graphics card (didn't work). I've used pro-support many times to see if there is anything that can be done. They are going to see about replacing my motherboard with one that is set up for non-redundant power. We'll see if that amounts to anything. If you configure the new 3930 racks on dell.com you can select non-redundant power. So maybe with that motherboard it will work and I'll finally have 1100w.

Sullen Saucier · Answer

Update: Yesterday I was able to get my external PSU to fire up the GPU while my 2 x internal PSU's run the rest of the system. It's a little less than ideal, but it is working so far.

Sullen Saucier · Answer

From my experience, I think by adding a second internal PSU and purchasing the Dell GPU power cable, your system should be able to use the NVIDIA Quadro RTX6000. Hope this helps!

JoeParker · Answer

Hi Sullen

Glad to hear you were able to get it working! I ended up buying a new server with the redundant power supply, but I still can't get the GPU to work. I'm using a regular PCIe GPU power cable, and from your results, it seems like I need the DELL GPU power cable. Unfortunately, I can't find one for the Precision. (I found one for a PowerEdge, but the connector is a different size.) Do you remember the part number, or do you have any information about the pin assignments and so forth?

Sullen Saucier · Answer

I hope the photos are clear enough to see the connections.

I got this cable for my 3930 rack:

GPU Power Cable (short 8x6)

Manufacturer Part MGKMR

Dell Part 470-ADFR

Order Code 470-Adfr

I found it under accessories for the 3930 rack in the business side of the house.

https://www.dell.com/en-us/shop/gpu-power-cable-short-8x6/apd/470-adfr/power-cooling-data-center-infrastructure

JoeParker · Answer

Thank you very much for the information and for the quick response!

I can't see the second picture, but from the first I can tell that the pin assignments are very different than the standard PCIe cable. Are the pins which are hidden in this image all grounds?

Pin assignments (that I think I can see).

? ? ? Yellow

Yellow(x2) GND(x2) GND GND

I looked for the cable on the DELL website, but it doesn't seem to be available here (I'm in Japan). I'll try asking them directly. If I can't get it from DELL, I think the only option will be to make the cable myself.

Thanks again. You've already been a big help.

Sullen Saucier · Answer

Here is the free end that I don't use.

Sullen Saucier · Answer

Happy to help! I'll attach better photos. I think these two will be the most helpful.

Sullen Saucier · Answer

I actually considered making my own cable at one point. I hope you are able to figure it out, it took me about a year and a half! So I am more than willing to help anyone in a similar situation. I've spent hours on the phone with dell representatives and salesmen. Let me know if there is anything else I can provide more detail on.

JoeParker · Answer

Thanks again! I've been fiddling with this off and on for close to a year now, myself.

These pictures are just what I needed. I'll try to modify my current cable to match and see if it makes a difference.

Precision Fixed Workstations

Precision 3930 Rack: Set up non-redundant power supply

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