• Guest, The rules for the P & N subforum have been updated to prohibit "ad hominem" or personal attacks against other posters. See the full details in the post "Politics and News Rules & Guidelines."

Question Can I make a second PSU power my GPU?

philosofool

Senior member
Nov 3, 2008
273
19
81
This is crazy stuff that I would never ordinarily do, however...

I teach at a university and we are now online due to COVID19. I need to prepare lecture videos for my students. HitFilm Express, my video editor, is GPU accelerated. My office computer has an i5 7500 but no standalone GPU. The result is a painfully slow video encoding experience. (BTW, I can't work from home because my wife does as a matter of course and uses that computer during the day.)

Now, I could add an older RX 270 to my office computer, but it's an Dell prebuilt that doesn't even have the power connectors, much less the power. So....

Can I bring in an old PSU from an old computer to power the RX 270, while the rest of the system works on the existing power supply? (The case for my Dell is ITX, my PSUs are ATX.)
 

Dribble

Golden Member
Aug 9, 2005
1,824
357
126
If you've got a psu and need a short term hack just unplug the dell one and plug everything into the the new one. The psu can sit outside the case.
 

philosofool

Senior member
Nov 3, 2008
273
19
81
If you've got a psu and need a short term hack just unplug the dell one and plug everything into the the new one. No need to try and use two. The psu can sit outside the case.
Right. I may have to try that. The power connectors on the mobo are weird (can't find the 24-pin (?) that usually plugs into it) but this is another option.
It occurs to me that the card height might not work, but I can give it a try. Thanks.
 

Max23B0

Junior Member
Mar 24, 2020
1
0
6
If you've got a psu and need a short term hack just unplug the dell one and plug everything into the the new one. The psu can sit outside the case.
Yes, but I wonder how many watts it is? enough for a video card or not!?
 

philosofool

Senior member
Nov 3, 2008
273
19
81
Yep. The PSU and the GPU were paired in an older system of mine, but parts of that system, including the Windows 10 license and SSD, were canibalized so I can't just bring it in to the office.
 

ondma

Golden Member
Mar 18, 2018
1,452
403
106
This is crazy stuff that I would never ordinarily do, however...

I teach at a university and we are now online due to COVID19. I need to prepare lecture videos for my students. HitFilm Express, my video editor, is GPU accelerated. My office computer has an i5 7500 but no standalone GPU. The result is a painfully slow video encoding experience. (BTW, I can't work from home because my wife does as a matter of course and uses that computer during the day.)

Now, I could add an older RX 270 to my office computer, but it's an Dell prebuilt that doesn't even have the power connectors, much less the power. So....

Can I bring in an old PSU from an old computer to power the RX 270, while the rest of the system works on the existing power supply? (The case for my Dell is ITX, my PSUs are ATX.)
Can you encode with Quick Synch? That is a built in encoding featue of skylake and later Intel cpus.
 
  • Like
Reactions: FaaR

philosofool

Senior member
Nov 3, 2008
273
19
81
You would expect it to have a spare molex or two because even dell machines add a hDD every now and then, right? I even have a molex to six pin, but I don’t think There are two spare molex. Besides, the psu is probably not meant to at 100+ Watts.
 

Bouowmx

Golden Member
Nov 13, 2016
1,023
397
116
"Add2psu"
Brand name for daisy chaining ATX power supply so that when one power supply turns on, the other turns on automatically.
 
  • Like
Reactions: psolord

Shmee

Memory and Storage, Graphics Cards
Super Moderator
Sep 13, 2008
4,513
578
126
I would recommend to buy a whole other PSU, they aren't that expensive, but, if the current dell one has proprietary connectors, that may not be an option.
 

DeathReborn

Platinum Member
Oct 11, 2005
2,188
125
106
The Dell might be one with a Mini-24 pin PSU connector, that can be resolved by using a adapter cable and a standard ATX/ITX PSU. You'd need to look up the model of the Dell to see if it matches the 24 Mini or uses one of their other random pin layouts. This is an example cable adapter.

 

Stuka87

Diamond Member
Dec 10, 2010
5,001
740
126
Will the GPU even FIT in the Dell? Those Dell ITX machines typically require a low profile video card. A full height card won't fit.

Outside of that, you can run both PSU's together, but you have to either manually turn on the secondary one (ground the green start wire), or, you can run a wire from the Dell's start wire to the other PSU so that they both start together. However, one thing to note, your secondary PSU may have a grounding issue because its not in the case. So you may want to run a ground wire from the secondary PSU to the Dell's chassis to prevent ground loops.
 

thesmokingman

Platinum Member
May 6, 2010
2,240
147
106
Now, I could add an older RX 270 to my office computer, but it's an Dell prebuilt that doesn't even have the power connectors, much less the power. So....

Can I bring in an old PSU from an old computer to power the RX 270, while the rest of the system works on the existing power supply? (The case for my Dell is ITX, my PSUs are ATX.)
Technically you can add a second psu, easily but your Dell might be a proprietary psu so you might be out of luck there. You need access to the green pin4 "PS ON#" in ATX spec. I've no clue what that is on Dell. If however your Dell is an ATX psu, you can get cable adapter for 10 bucks or so maybe more, there's also Phanteks power Combo.
 

Steltek

Platinum Member
Mar 29, 2001
2,383
279
126
Specifically what model Dell do you have? Kind of hard to make realistic recommendations without knowing that first.
 
  • Like
Reactions: Muadib

sdifox

No Lifer
Sep 30, 2005
80,384
7,271
126
Yep. The PSU and the GPU were paired in an older system of mine, but parts of that system, including the Windows 10 license and SSD, were canibalized so I can't just bring it in to the office.
Move the hdd from the dell to your partial rig?
 

philosofool

Senior member
Nov 3, 2008
273
19
81
"Add2psu"
Brand name for daisy chaining ATX power supply so that when one power supply turns on, the other turns on automatically.
Nice. I'm going to try this. It looks like I'm going to have to move the board to another case, and btw it's actually microATX, not ITX, but it is low profile and I have a spare case that is. Further inspection reveals that the regular PSU is proprietary and has weird connectors, so I have just swap out with a different one.

(I have been sitting in my office waiting 33 minutes, still not finished, with my video export.)
 

Stuka87

Diamond Member
Dec 10, 2010
5,001
740
126
Nice. I'm going to try this. It looks like I'm going to have to move the board to another case, and btw it's actually microATX, not ITX, but it is low profile and I have a spare case that is. Further inspection reveals that the regular PSU is proprietary and has weird connectors, so I have just swap out with a different one.

(I have been sitting in my office waiting 33 minutes, still not finished, with my video export.)
Did you ever try using Quick Sync?
 
  • Like
Reactions: darkswordsman17

Feld

Senior member
Aug 6, 2015
282
90
101
I can tell you from my mining experience that it's a bad idea to have a GPU be powered by one PSU on its 6/8 pins but a different PSU on the slot. So you either want to replace the PSU supplying the whole system to something that is compatible with both the motherboard and GPU, or if you are going to use two PSUs then you can use a powered riser to connect the GPU to and be sure to power the riser using the same PSU that is connected to the 6/8 pin plug(s) on the GPU. Powering one card from more than one PSU can cause instability or potentially even damage to the card from even slight phase or power delivery variations coming from the two PSUs (though I'm no expert on the electrical details).
 
  • Like
Reactions: Headfoot

ondma

Golden Member
Mar 18, 2018
1,452
403
106
On a different tack, what about adding a newer dgpu that doesnt require external power?
Something like a GTX 1030, 1050, or 1050Ti.
 
Mar 11, 2004
20,290
2,435
126
Did you ever try using Quick Sync?
I really don't understand why the OP is ignoring this, or why everyone in the thread isn't mentioning it. GPU processed is going to use the encoding block of the card, or its going to still take a long time. Why not just use the encoding block already there?
 

Steltek

Platinum Member
Mar 29, 2001
2,383
279
126
I really don't understand why the OP is ignoring this, or why everyone in the thread isn't mentioning it. GPU processed is going to use the encoding block of the card, or its going to still take a long time. Why not just use the encoding block already there?
Hitfilm Express (his video editor) does not use either Quicksync or CUDA. It apparently isn't coded to use any type of proprietary encoding solutions. From what I can tell, it only uses OpenGL.
 
Last edited:

Headfoot

Diamond Member
Feb 28, 2008
4,435
624
126
I can tell you from my mining experience that it's a bad idea to have a GPU be powered by one PSU on its 6/8 pins but a different PSU on the slot. So you either want to replace the PSU supplying the whole system to something that is compatible with both the motherboard and GPU, or if you are going to use two PSUs then you can use a powered riser to connect the GPU to and be sure to power the riser using the same PSU that is connected to the 6/8 pin plug(s) on the GPU. Powering one card from more than one PSU can cause instability or potentially even damage to the card from even slight phase or power delivery variations coming from the two PSUs (though I'm no expert on the electrical details).
I second this opinion, I had similar weird spottiness issues when using Add2PSU for mining. It worked most of the time though.

I'd definitely look into buying the specific 24Pin ATX Standard connector -> Dell proprietary adapter mentioned earlier in the thread and using a more powerful off the shelf regular PSU.
 

philosofool

Senior member
Nov 3, 2008
273
19
81
I can tell you from my mining experience that it's a bad idea to have a GPU be powered by one PSU on its 6/8 pins but a different PSU on the slot. So you either want to replace the PSU supplying the whole system to something that is compatible with both the motherboard and GPU, or if you are going to use two PSUs then you can use a powered riser to connect the GPU to and be sure to power the riser using the same PSU that is connected to the 6/8 pin plug(s) on the GPU. Powering one card from more than one PSU can cause instability or potentially even damage to the card from even slight phase or power delivery variations coming from the two PSUs (though I'm no expert on the electrical details).
The board has the most ridiculous ATX system power connector I have ever seen. 6 pins? Is it possible that that is the same configuration as a 6-pin PCIe? If so, I could put the whole board on a different PSU. But I have no idea how to check whether the board ATX_SYS 6-pin is the same as a PCIe 6-pin and rule #1 here is don't fry your work computer. This is (I hope) a temporary situation or I would invest in a real solution.

If not, I can't find a riser that's compatible with the board, which has PCIE 4x and 16x but not 1x, which is what all the risers use. In any event, video rendering should be less power intensive and should run for shorter periods of time than mining, so hopefully it will be stable.
 

ASK THE COMMUNITY

TRENDING THREADS