@Ford_Prefect2 The Service Manual shows a pictures (on pages 38 & 39) of a graphics card with an 8 pin connector and a 6 pin connector and power cables connected to them. Check to see if there is an unused 8 pin connector available.

Hi Vic384,

Thanks for your interest and your response.

I have the GTX 1660 graphics card which only has one 8 pin connector.

My problem is that the PSU lead to the card only has 6 pins and I can't find anybody at Dell who can tell me if this is OK or whether it should be an 8 pin connector.

Hence my request to see if anyone out there has a GTX 1660 and how many pins the PSU cable has.

Thanks again for your interest.

Hi,

Thanks for the info and your continued interest.

My PSU is model PCFT5 and only has one 6-pin cable for graphics card.

The other three cables go to the motherboard.

Having looked round the GeForce and NVIDIA forums it's seems possible that my PSU is incompatible with my graphics card.  A guy from Dell is currently checking the specification for me. I'll keep you posted.

Regards.

@Ford_Prefect2  In my XPS 8940, the power cable from the PSU to the graphics card has both an 8-pin plug (plugged into the RTX 2060) and a 6-pin plug.  I have the Chicony 500W power supply, Dell P/N Y7R0X.

XPS 8940 power cable.

360w is the standard unit.  More than that has options for front case fan as well as a six and 8 pin connector rated at 12v 18 amps max. PCFT5 is used by G5 5090, XPS 8940, and Optiplex 7080

You don't get a free 500w upgrade by accusing dell of putting in the wrong power supply.

Your service tag would show what is what.

@DELL-Chris M  would have more information.

DO NOT SEND ME your service tag I do not work for Dell.

DO NOT POST your service tag in the forum.

I see none of these in the parts finder.
https://www.dell.com/en-us/work/shop/dell-parts-finder/cp/dpf

XPS 8940, Inspiron G5 5000, Inspiron G5 5090
PSU

2VD0G 360w Liteon
5K7J8 500w Delta
99TPH 500w Liteon
Y7R0X 500w Chicony

https://www.ebay.com/itm/DELL-Power-Supply-500W-Y7R0X/194040570385

H360EBM PCFT5 is only 360W which is why it DOES NOT OFFER an 8 pin connector.

PSU
2VD0G 360w Liteon
5K7J8 500w Delta
99TPH 500w Liteon
Y7R0X 500w Chicony

@DELL-Chris M  would have more information.

8 pin implies 225w to 300w GPU.

Aka 75w from slot and 150w from Aux power

Hi Vic,

The PSU has been replaced twice but I never saw the original one.

So I'm now thinking it came with the correct supply, obviously, but has been swapped out for a different one?

Thanks very much for the information on the PSU.

I have asked Dell support to confirm that I have compatible parts.

Not a Dell PSU I've seen referenced for the XPS 8940 before.  The one's I'm aware of are:

2VD0G - 360w Liteon,
5K7J8  - 500w Delta,
99TPH - 500w Liteon,
Y7R0X - 500w Chicony.

@Ford_Prefect2 If your new XPS 8940 can with the GTX 1660 graphics card I can't see how it is not compatible.

12v 18A is a fire safety limit UL94v

Re: One strange thing I noticed is that the graphics card has an 8-pin power socket but the power cable from the power supply only has 6 pins.

you just need a 6 pin to 8 pin straight adapter to provide additional gnd connector. When a 6 pin has all three 12V wires, it is as good as an 8 pin in terms of power it can deliver.  The 8 pin has only three 12V wires too, but additional gnd wires in the extra 2 pin.  You often see the 6+2 pin which is exactly 6 pin + 2 gnd pin to make it an 8 pin.

you do not need the top 500w psu to power 1660.  360w Dell psu with only one 6 pin is good enough if you use a 6 to 8 pin adapter.

Using online basic psu calculator if you have i9-10900k, 32gb ddr4, 1660, nvme ssd, recommended psu is 364w.Load Wattage: 314 W
Recommended PSU Wattage: 364 W
Dell psu spec is often exactly on par with estimate, extra power not needed for your spec. If you ever upgrade to 3000 series psu then a 500w Dell psu is warranted.

@redxps630 

"you just need a 6 pin to 8 pin straight adapter to provide additional gnd connector."

This is very bad advice.

"6 pin has all three 12V wires, it is as good as an 8 pin in terms of power"  This is false. Safe 8 pin adapters combine 12 wires aka dual 6 pin 150w = Single 8 pin 225W - 300W as noted in the PCI SIG spec. 5 12v wires are required for the 8 pin.  Jumpering pins together to fake out the gpu does not provide additional power and sense lines which is why it REQUIRES 2 six pin connectors to make ONE 8 pin connector. Dell doesn't provide the six and 8 together implying 375W power on a single cable.

Connectors and Pinouts

Single 6 pin to 8pin cables are not safe and not supported. Has nothing to do with PSU and everything to do with UL94v safety and the current rating of the wires and molex pins. 360W unit as well as the XE2 315w unit only have ONE six pin for a reason.

He already noted he has the 360W unit.

8pin implies that there is 225 - 300W extra for the GPU alone.  Not happening with a 360W power supply.

Adding a 6 pin to 8 pin cable DOES NOT provide more power from your power supply. This is very well documented since 2004 spec 1.0

Unsafe Non Supported cable

@Ford_Prefect2 If your original PSU has been swapped out it appears that a PSU that is not compatible with your configuration of the XPS 8940 was installed. If you go to the Dell support site and enter your Sevice Tag you should be able to see the as shipped original configuration of your system if you click on the 'View product specs' link.