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June 15th, 2022 14:00
XPS 8950, 1000w PSU
I recently placed an order for an XPS 8950 and noticed the option for a 1000w PSU. I checked the FAQ but did not find any info on this option. Does anyone have details on this PSU? I'd like to know the type (Gold, Platinum) manufacturer and the number of 6/8pin PCIe plugs. I'd like to use an EVGA RTX 3070 Ti but it needs 3 8pin PCIe power connections.
Chassis Options
1000W Platinum Silver Bezel Chassis including optical drive
Item number: 321-BHTZ
Thanks.
Zeebrock
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June 24th, 2022 12:00
So my Dell XPS 8950 was delivered. I took some pictures of the 1000w PSU installed.
It's the RD0G0 1000W Delta unit, 80 PLUS - Platinum. The good news is the +12V rails are high current, the bad news is there seem to be only 2 Video/PCIe cables each with a 6-Pin and piggy-back 8-Pin PCIe connector. Plenty for the cards that only have 2 PCIe connectors, but installing an RTX 3090Ti for example will need a Y cable 6-Pin+6Pin-8-Pin like this: https://www.amazon.com/Female-TeamProfitcom-Adapter-Braided-Sleeved/dp/B07V4GGS43 to get the required 3x 8-Pin PCIe connectors.


The 6-Pin PCIe connectors on this PSU have 3x +12V pins, normally 6-Pin PCIe connectors only have 2x +12V pins. This was done presumably to be able to correctly supply the PCIe 8-Pin connectors that require 3x 12V pins. The cable used is 18AWG Polypropylene Polyethylene that is rated at 17A/90C, maximum capacity 6x17A=102A @12v, this clearly is more than the PSU rating for both rails, 2x 36A @12v. So if we go by the PSU rating of 72A @12v to give us a total of 864W. Now, these are ideal maximums however, looking at an RTX 3090 Ti it has a rated reference of 450W-480W total draw. Some cards hit as much as 490W total in synthetic benchmarks. Even if we call it 500W and assume all of it gets drawn from the PCIe connectors and none from the slot we are still in a good place (500W demand vs 864W capacity). So using a Y cable would spread the load over a total of 6 +12V cables with the rating and capacity to supply the power needed.
+12VA = 36A
+12VB = 27A
+12VC = 36A
RoHe
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June 15th, 2022 16:00
As of now, the largest PSU listed for the XPS 8950 by @DELL-Chris M is 750W. Maybe he can update the FAQ page...
kras1
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June 15th, 2022 17:00
I was a little surprised to see a 1000 watt PSU being sold in the new XPS 8950's. I wish that was available when I got mine..... oh well, I guess that is what happens when ya order one on the first day it goes on sale.
redxps630
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June 15th, 2022 17:00
750W PSU has four PCIe connectors (6pin*2, 6+2pin*2)
XPS 8950 and Aurora R13/R14 use same PSU.
FAQ XPS 8950
43YPM 1000W Acbel (XPS 8950, Aurora R13/R14, Precision 3660)
R61D8 1000W Liteon (XPS 8950, Aurora R13/R14, Precision 3660)
RD0G0 1000W Delta (XPS 8950, Aurora R13/R14, Precision 3660)
MP23Y 750W, Acbel (XPS 8950, Aurora R13/R14, Precision 3660)
M92DC 750W, Chicony (XPS 8950, Aurora R13/R14, Precision 3660)
M2G8X 750W, LiteOn (XPS 8950, Aurora R13/R14, Precision 3660)
PNWT1 460W Bronze, Acbel (XPS 8950, Aurora R13/R14)
389MC 460W Bronze, Chicony (XPS 8950, Aurora R13/R14)
T63HC 460W Bronze, Huntkey (XPS 8950, Aurora R13/R14)
HD2W8 300W, Acbel (XPS 8950, Precision 3460/3660, Optiplex 3000/5000/7000)
3XY3J 300W, Chicony (XPS 8950, Precision 3460/3660, Optiplex 3000/5000/7000/XE4)
6R2MV 300W, Delta (XPS 8950, Precision 3460/3660, Optiplex 3000/5000/7000/XE4)
MJXT6 300W, LiteOn (XPS 8950, Precision 3460/3660, Optiplex 3000/5000/7000/XE4)
Aurora R14, 1000W PSU?
ProfessorW00d
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June 15th, 2022 18:00
Does anyone know if the 1000 watt PSU has three 8-pin PCIe power cables, per OP's question?
speedstep
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June 16th, 2022 13:00
@ProfessorW00d
NONE of ANY Dell 1000W have Three 8 pin. Each 8 pin represents 375W of 12v power. Which is why you need 1200 to 1600w psu for some configs that have dual 3090.
Corsair AX1600i is needed for Overclocking and 1 or 2 3090 cards for record breaking.
Corsair AX1600i Power Specs;
Rail: 3.3V: 5V: 12V: 5VSB-12V:
Max.
5.0v 30A
3.3v 30A
133.3A for 12v
3.5A 5vSB 17.5W
0.8A: -12v
1600W total
180W 3.3v / 5v combined max
Total Max. Power: 1600W
redxps630
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June 16th, 2022 13:00
750w psu has four PCIe connectors (6pin*2, 6+2pin*2)
that is equivalent to three 8 pins. there are already two 8 pins. the two 6 pins can become a third 8 pin via standard adapter off the shelf.
750W M92DC is 80 plus platinum.
https://www.dell.com/community/XPS-Desktops/XPS-8950-750W-psu-available-super-expensive/m-p/8218977#M72726
Zeebrock
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June 16th, 2022 14:00
I'm not sure where you get 375W for an 8-pin PCIe connector unless you are quoting the rating for the 12v rail associated with that connector. If that is the case then that value will be different depending on the make/model of PSU and is by no way a standard number.
The PCIe "standard" for an 8-pin connector is 150w, now we know that is more of a guide than a standard. The RTX 3090 Ti will draw between 170-180w from each of its 3 8-pin connectors as measured in a recent test performed by GN. It is not unreasonable to expect a 1000W PSU to be able to accommodate a single RTX 3090 Ti. Hence my question is, does the Dell 1000W PSU have 3x 8-pin PCIe connectors?
I see that the 750W PSU has 2x 8-pin (6+2) and 2x 6-pin PCIe connectors so worst case if the 1000W has the same I can use the 2x 8-pin's and then a 2x 6-pin to 1x 8-pin Y cable.
speedstep
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June 16th, 2022 20:00
@Zeebrock
375W is based on 300W from the 8 pin connector and 75W from the PCI-E connector based on PCI-E 1.1 spec. As bandwidth goes up so do the power requirements which is why its not one six pin 150W or 1 eight pin 300W its dual 8 pin meaning 300W + 300W + 75W slot. Single Six pin goes up to 225W aka 150W + 75W slot. This is why the FSP Booster power supply is 450W for VIDEO POWER ONLY.
FSP-PCI-Express-X5/dp/B002IZE5RE
Power supplies are NOT a single spec of WATTS or a single rail. Max volts and Amps on ANY connector is 12v 18 Amps. That's fire safety UL 94v spec. Nothing whatsoever to do with WATTS of power supply and everything to do with the number of wires carrying the 12v DC current. Those are hard limits based on fire safety. Doubling up connectors or converting 6 to 8 without 8 wires IS NOT ADDING POWER to the PSU or safe to do. It is in fact not safe. CPU 4 + 4 EPS12v is not GPU 6 + 2
These numbers ARE Standard Across ALL EPS12v UL 94v certified power supplies, all vendors. ATX is not used since 1995 being only 75 percent efficient max vs 80 percent EPS12v.
Number of pins or fitting into a connector or fooling bios with jumpers is not the same as having actual power. combined power on 3.3v/5v rails should be 25 to 30 AMPS and 150W to 225W. Not all power supplies even 1000W units meet that spec.
Zeebrock
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June 17th, 2022 05:00
You said, and I quote "Each 8 pin represents 375W of 12v power" that is where to confusion came from. The 8-pin PCIe Video Molex connector has either 2x or 3x separately supplied 12v pins and "can" therefore supply up to 216w or 288w (also depending on the gauge of wire the PSU manufacturer uses). The PCIe slot can also supply up to 75w however, it is not a one-to-one ratio. You can use 2 8-pins on one video card, that would not be 375w + 375w as you (maybe) suggested, it would be 150w + 150w + 75w or 216/288w + 216/288w + 75w.
Also using 2x 6pins with a Y cable would (and does) work. The 6-pin Molex connector has 2x separately supplied 12v pins and can provide up to 216w, with the appropriate Y cable adapter this would easily exceed the 150w "standard" and could supply up to the limit of the 8-pin connector on the end of the Y cable. I use good quality Y cables with 14 gauge wires.
I Crypto mine and I am very familiar with the physical limits of cables and connectors, I am also an Electrical Engineer so I have a better than most understanding of power circuits. But I feel we are getting away from my original (simple) question of how many 6/8-pin PCIe Video connectors the Dell 1000w PSU has. Hopefully if my 8950 gets delivered on time I will be able to answer it myself. I'll post the info here as well for others to benefit from.
Thanks.
Zeebrock
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June 17th, 2022 06:00
I went with the i7-12700k, that's why I was so happy to see the 1000w PSU option.
ProfessorW00d
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June 17th, 2022 06:00
OK, that should definitely need the max power. What CPU are you pairing with that graphics card?
I also typo'ed as my RTX 3080 FE is powered by three 6-pin PSU ports cabled to the nVidia 12-pin connector.
ProfessorW00d
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June 17th, 2022 06:00
The EVGA RTX 3070 is a 290 watt graphics card, so that third PCIe 8-pin power connector must be a decoration for the easily amused. I have an RTX 3080 FE @ 320 watts that is powered by two 6-pin PSU ports cabled to the nVidia 12-pin connector. Keep us appraised of the cables you find on the XPS 8950 1000 watt PSU.
Zeebrock
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June 17th, 2022 06:00
Good catch, my mistake. I typo'ed I meant to say RTX 3090 Ti
speedstep
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June 24th, 2022 15:00
@Zeebrock
"Does anyone have details on this PSU?"
No and Dell does not publish schematics or documentation or which ODM they use for their OEM power supplies.