Computers External Video Card Help

Chief Pagan · 09-23-2023, 04:12 PM

Shorter story:
I have a small form factor Dell desktop with a 1/2 slot card. I'm contemplating using a PCI 3.0X16 riser cable and just setting the video card with an external power supply outside of the box.

Is this viable?

Chief Pagan · 09-23-2023, 04:13 PM

Longer story

I bought an OptiPlex 5080 and I haven't added memory or a card to a computer in probably 15 years so I didn't think twice about going with the small form factor. It is a relatively powerful machine i7/64Gb with plenty of cores because of number crunching stuff I do for work. And I don't really like messing with computers, so I tend to buy an overpowered machine so I don't have to replace them as often.

Well now I am interested in more video processing. Of all things, Baldur's Gate 3 caught my eye and my work software has gotten more video intensive. When I started talking about that, a work buddy even offered to give me (sell cheap) a ZOTAC GeForce GTX 1660 Super 6GB GDDR6 192-bit Gaming Graphics Card and Thermaltake Smart 500W 80+ White Certified PSU, Continuous Power with 120mm Ultra Quiet Cooling Fan, ATX 12V V2.3/EPS 12V Active PFC Power Supply PS-SPD-0500NPCWUS-W. (I don't think the small form factor has enough power for the video card on its own.)

So is it as simple as ordering this:

GLOTRENDS PCIe 3.0 X16 GPU Riser Cable Length 600mm, Female 180 Degree Angle:

https://www.amazon.com/GLOTRENDS-Com...37&sr=8-3&th=1

And running this out of the box?

Is it okay to hook up the external power supply to the video card even though the video card is connected to the mother board through the riser cable? I've gotten mixed commentary on this from YouTube.

Is this Cable going to be flexible enough that I can it loop and twist and run it out the slot/opening where the 1/2 card would normally be? My brother thinks it will be. I'm rather doubtful, but not sure. Would the strategy be to cut a hole in the top of the desktop box to get the cable out?

I'll post a picture in the next reply.

Any advice?

Chief Pagan · 09-23-2023, 04:14 PM

Inside:

Fish · 09-23-2023, 07:21 PM

I'm not confident that would work using an external power source while still connected to the motherboard bus via the riser cable. Wouldn't the system still try and provide voltage via the PCIe port? It doesn't know the difference between a riser card or normal GPU. Usually an eGPU that has independent external power would connect via Thunderbolt. If it did work, it would likely cause your power management system to shit its pants.

The more I think about it, the more it sounds impossible for voltage reasons.

Mephistopheles Janx · 09-23-2023, 08:42 PM

You should absolutely be able to do it... I have done it myself before when testing PSUs. Not with a riser but by plugging the video card into a PSU I had on a work bench. It is how I figured out, without a voltmeter, that one of my PCIe plugins wasn't putting out power.

The slot is going to give the card its first 75w of power and the video card would simply draw the remainder of what it needed from the PSU.

My bigger concern is that you will wind up eating up a lot of extra desk space in order to have a place to mount the PSU and graphics card like an ITX bench or something of that nature.

Not recommending this one... just an example:

https://www.amazon.com/Overclock-Ver...7-93deae8f9840

---

To be real... you would probably be better served by buying a motherboard and case then transferring the internals (CPU, Memory/RAM, Storage, other drives) of the Optiplex into a standard form factor. From there just install your new video card and off you go.

If you have the room to spare... then by all means mount the PSU and the GPU onto a test bench, connect the ribbon cable, and call it a day.

Chief Pagan · 09-23-2023, 10:03 PM

Uh thanks?

More conflicting messages about whether the external power supply interferes with the motherboard but I guess I'll go with the people that say they have done it.

I had not considered transferring the guts of computer into a larger frame.

I have space behind the monitor, so it's not a deal breaker. But I do see it as awkward to have the external video card just floating around and I had looked into frames to hold it.

I'm not keen to disassemble my functioning computer. I mean, I'm not completely clueless, but don't break it if it is working... But I will think that one over.

Thanks.

mdstu · 09-27-2023, 03:07 PM

Quote:

Originally Posted by Chief Pagan

Uh thanks?

More conflicting messages about whether the external power supply interferes with the motherboard but I guess I'll go with the people that say they have done it.

I had not considered transferring the guts of computer into a larger frame.

I have space behind the monitor, so it's not a deal breaker. But I do see it as awkward to have the external video card just floating around and I had looked into frames to hold it.

I'm not keen to disassemble my functioning computer. I mean, I'm not completely clueless, but don't break it if it is working... But I will think that one over.

Thanks.

While probably not advised, it is possible to do. However, it's not as simple as just plugging the new PSU into the video card.

Found on forum:

https://linustechtips.com/topic/1063...%20motherboard.

The PSU's need to come on at the same time. Two options below.

1. Bridge the new PSU and switch it on at the same time you push your PC power button.
2. Make new connector/Rig wiring to both PSUs to receive POWER_OK signal from motherboard.

I read somewhere that there would be risk if power problems occurred and the second PSU didn't receive signal from MB to shut down. I don't know if the second option resolves this risk or if the signals are occurring through the 24pin connector.

mdstu · 09-27-2023, 03:22 PM

Disclaimer: I am not an expert. Just a guy that builds my own PC's and tinkers with tech stuff.

Otter · 09-27-2023, 04:47 PM

This sounds like you're trying to make your 1970 AMC Gremlin look cool.

Fish · 09-27-2023, 04:51 PM

If you try it, you should definitely record it...

Chief Pagan · 09-29-2023, 09:03 PM

Short answer:

It seems to be working after some trouble shooting with the PSU.

Long answer:

Everything that draws power is plugged into the same power strip that I turn on so things should basically get power at the same time.

I plugged the 16 extender cable in into the available slot. The cable does twist out of the opening in the back of the computer so I can close the lid normally. I'm a little nervous about the strain on the cables, but I'll guess we will see.

Plugged the external video card to the other end of the cable. Plugged the power PCI whatever thingy to the video card, switched over the display port to the video card...

Took a deep breath, turned everything on...

Black screen.

It didn't look like the computer recognized there was a video card plugged in. Switched the DP back directly to the desktop and got a signal from the old 630.

Hhmm, nothing appeared to be happening with the video card. No lights, and no motion from the fan. Does the fan not run until it gets hot? Or should it run immediately?

Hhmm, the PSU doesn't appear to do anything. It doesn't appear to have any light to let you know that it is on. Should the fan on the PSU run immediately, or only after it gets hot?

Hoo boy. I'm not thrilled messing with this.

YouTube 'is my PSU bad?'

So you can run a paper clip between the third and fourth pin on the motherboard power supply to check if the PSU works. Hey, when I do that, the fan turns on. Not only does the fan turn on, but now my voltmeter shows that the PCI power supply for the video card now has voltage.

Great, so all I have to do is leave a paper clip to short out the motherboard power supply cable in order to make the video card power supply cable hot.

I kid not.

Hook shit back.

Hey, PSU fan on. Check.

Video card fan on. Check.

Video signal from video card when I turn the computer on. CHECK. CHECK. CHECK.

So far, it appears to be working great.

NVIDIA drivers automatically installed. Check.

Time to break out the Rye.

Chief Pagan · 09-29-2023, 09:13 PM

Quote:

Originally Posted by mdstu

While probably not advised, it is possible to do. However, it's not as simple as just plugging the new PSU into the video card.

Found on forum:

https://linustechtips.com/topic/1063...%20motherboard.

The PSU's need to come on at the same time. Two options below.

1. Bridge the new PSU and switch it on at the same time you push your PC power button.
2. Make new connector/Rig wiring to both PSUs to receive POWER_OK signal from motherboard.

I read somewhere that there would be risk if power problems occurred and the second PSU didn't receive signal from MB to shut down. I don't know if the second option resolves this risk or if the signals are occurring through the 24pin connector.

So this referenced the paper clip trick and I later also figured it out.

I've seen so much conflicting advice...

Hard to know what to take seriously or not...

Chief Pagan · 09-29-2023, 09:20 PM

I have a frame but haven't yet tried to get the video card and PSU into the frame. I thought I would see if I could get it to work first. I guess that's next. Don't really want to leave the video card just lying on the table very long.

09-23-2023, 04:12 PM
Chief Pagan Sometimes it's black and white Join Date: Nov 2004 Location: California Casino cash: $3784900	External Video Card Help Shorter story: I have a small form factor Dell desktop with a 1/2 slot card. I'm contemplating using a PCI 3.0X16 riser cable and just setting the video card with an external power supply outside of the box. Is this viable?
Posts: 6,138

09-23-2023, 04:13 PM	#2
Chief Pagan Sometimes it's black and white Join Date: Nov 2004 Location: California Casino cash: $3784900	Longer story I bought an OptiPlex 5080 and I haven't added memory or a card to a computer in probably 15 years so I didn't think twice about going with the small form factor. It is a relatively powerful machine i7/64Gb with plenty of cores because of number crunching stuff I do for work. And I don't really like messing with computers, so I tend to buy an overpowered machine so I don't have to replace them as often. Well now I am interested in more video processing. Of all things, Baldur's Gate 3 caught my eye and my work software has gotten more video intensive. When I started talking about that, a work buddy even offered to give me (sell cheap) a ZOTAC GeForce GTX 1660 Super 6GB GDDR6 192-bit Gaming Graphics Card and Thermaltake Smart 500W 80+ White Certified PSU, Continuous Power with 120mm Ultra Quiet Cooling Fan, ATX 12V V2.3/EPS 12V Active PFC Power Supply PS-SPD-0500NPCWUS-W. (I don't think the small form factor has enough power for the video card on its own.) So is it as simple as ordering this: GLOTRENDS PCIe 3.0 X16 GPU Riser Cable Length 600mm, Female 180 Degree Angle: https://www.amazon.com/GLOTRENDS-Com...37&sr=8-3&th=1 And running this out of the box? Is it okay to hook up the external power supply to the video card even though the video card is connected to the mother board through the riser cable? I've gotten mixed commentary on this from YouTube. Is this Cable going to be flexible enough that I can it loop and twist and run it out the slot/opening where the 1/2 card would normally be? My brother thinks it will be. I'm rather doubtful, but not sure. Would the strategy be to cut a hole in the top of the desktop box to get the cable out? I'll post a picture in the next reply. Any advice? __________________ Sometimes. Last edited by Chief Pagan; 09-23-2023 at 04:19 PM..
Posts: 6,138

09-23-2023, 04:14 PM	#3
Chief Pagan Sometimes it's black and white Join Date: Nov 2004 Location: California Casino cash: $3784900	Inside: Attached Thumbnails __________________ Sometimes.
Posts: 6,138

09-23-2023, 07:21 PM	#4
Fish Ain't no relax! Join Date: Sep 2005 Casino cash: $2308919	I'm not confident that would work using an external power source while still connected to the motherboard bus via the riser cable. Wouldn't the system still try and provide voltage via the PCIe port? It doesn't know the difference between a riser card or normal GPU. Usually an eGPU that has independent external power would connect via Thunderbolt. If it did work, it would likely cause your power management system to shit its pants. The more I think about it, the more it sounds impossible for voltage reasons. __________________
Posts: 47,478

09-23-2023, 08:42 PM	#5
Mephistopheles Janx The Demon Preacher Join Date: Jan 2017 Casino cash: $2012400	You should absolutely be able to do it... I have done it myself before when testing PSUs. Not with a riser but by plugging the video card into a PSU I had on a work bench. It is how I figured out, without a voltmeter, that one of my PCIe plugins wasn't putting out power. The slot is going to give the card its first 75w of power and the video card would simply draw the remainder of what it needed from the PSU. My bigger concern is that you will wind up eating up a lot of extra desk space in order to have a place to mount the PSU and graphics card like an ITX bench or something of that nature. Not recommending this one... just an example: https://www.amazon.com/Overclock-Ver...7-93deae8f9840 --- To be real... you would probably be better served by buying a motherboard and case then transferring the internals (CPU, Memory/RAM, Storage, other drives) of the Optiplex into a standard form factor. From there just install your new video card and off you go. If you have the room to spare... then by all means mount the PSU and the GPU onto a test bench, connect the ribbon cable, and call it a day.
Posts: 9,916

09-23-2023, 10:03 PM	#6
Chief Pagan Sometimes it's black and white Join Date: Nov 2004 Location: California Casino cash: $3784900	Uh thanks? More conflicting messages about whether the external power supply interferes with the motherboard but I guess I'll go with the people that say they have done it. I had not considered transferring the guts of computer into a larger frame. I have space behind the monitor, so it's not a deal breaker. But I do see it as awkward to have the external video card just floating around and I had looked into frames to hold it. I'm not keen to disassemble my functioning computer. I mean, I'm not completely clueless, but don't break it if it is working... But I will think that one over. Thanks. __________________ Sometimes.
Posts: 6,138

09-27-2023, 03:22 PM	#8
mdstu Let's get a snack Join Date: Apr 2002 Location: Cincinnati Casino cash: $1618901	Disclaimer: I am not an expert. Just a guy that builds my own PC's and tinkers with tech stuff.
Posts: 1,353

09-27-2023, 04:51 PM	#10
Fish Ain't no relax! Join Date: Sep 2005 Casino cash: $2308919	If you try it, you should definitely record it... __________________
Posts: 47,478

09-29-2023, 09:03 PM	#11
Chief Pagan Sometimes it's black and white Join Date: Nov 2004 Location: California Casino cash: $3784900	Short answer: It seems to be working after some trouble shooting with the PSU. Long answer: Everything that draws power is plugged into the same power strip that I turn on so things should basically get power at the same time. I plugged the 16 extender cable in into the available slot. The cable does twist out of the opening in the back of the computer so I can close the lid normally. I'm a little nervous about the strain on the cables, but I'll guess we will see. Plugged the external video card to the other end of the cable. Plugged the power PCI whatever thingy to the video card, switched over the display port to the video card... Took a deep breath, turned everything on... Black screen. It didn't look like the computer recognized there was a video card plugged in. Switched the DP back directly to the desktop and got a signal from the old 630. Hhmm, nothing appeared to be happening with the video card. No lights, and no motion from the fan. Does the fan not run until it gets hot? Or should it run immediately? Hhmm, the PSU doesn't appear to do anything. It doesn't appear to have any light to let you know that it is on. Should the fan on the PSU run immediately, or only after it gets hot? Hoo boy. I'm not thrilled messing with this. YouTube 'is my PSU bad?' So you can run a paper clip between the third and fourth pin on the motherboard power supply to check if the PSU works. Hey, when I do that, the fan turns on. Not only does the fan turn on, but now my voltmeter shows that the PCI power supply for the video card now has voltage. Great, so all I have to do is leave a paper clip to short out the motherboard power supply cable in order to make the video card power supply cable hot. I kid not. Hook shit back. Hey, PSU fan on. Check. Video card fan on. Check. Video signal from video card when I turn the computer on. CHECK. CHECK. CHECK. So far, it appears to be working great. NVIDIA drivers automatically installed. Check. Time to break out the Rye. __________________ Sometimes.
Posts: 6,138

09-29-2023, 09:20 PM	#13
Chief Pagan Sometimes it's black and white Join Date: Nov 2004 Location: California Casino cash: $3784900	I have a frame but haven't yet tried to get the video card and PSU into the frame. I thought I would see if I could get it to work first. I guess that's next. Don't really want to leave the video card just lying on the table very long. __________________ Sometimes.
Posts: 6,138