Question Setting up a Graphics Card to run outside the case and external power!

Apr 27, 2021
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Hello all,

I am a newbie here.

So I made a purchase of a office desktop (a SFF) from Lenovo- M90S. Should have went with the big tower and would have not had this issue.

The SFF doesn't have a Graphics Card. It is an office pc with i7-10700 and 68 GB of memory and 380W PSU. System Specs

It has a free 3.0 x16 PCIe and 3.0 x4 PCIe expansion slot and I want to add a GPU. However, given the size of the case, I cannot install a proper GPU. Only low profile GPU which is not helpful (the performance is not as good).

The PC is mostly used by significant other for office work. Me on the other hand would like to use it for gaming and thus add a GPU. The GPU doesn't need to run all the time and the gaming/sim racing rig will have a separate monitor altogether, so no issue there either. Also, the GPU will be used maybe 4-5 times a month.

The built in Intel UHD can power the standard monitors for office work.

My idea is this:

i) Use a PCIe Kickstand Kickstand
ii) Connect the PCIe cable to the empty slot in the PC. Use the PCIe Slot/Brack to run the cable.

My main issue is the power supply for the GPU. The 380W PSU that my system has can supply power to GTX 1650 Super without any issue.

But if I want to use a more powerful GPU, I will need more juice. I will need to use another power source. What are my option? Can I buy a 500-800 watt PSU and use the 6 pin and 8 pin connector, just to power up the GPU?

I understand the GPU would have a separate On/Off switch and a separate power supply and not be controlled through the PC's PSU and motherboard. Would this be a workable setup?

Just turn on the PC normally, then turn on the PSU for the GPU and connect the 3rd monitor to the GPU for gaming!

Or does the GPUs power need to be controlled through the motherboard?

I can put the external PSU and the GPU on a RIG, or find a way to put it on the gaming RIG and connect it to the PC when needed?

Any advise or suggestion would be greatly appreciated.
 
Hello all,

I am a newbie here.

So I made a purchase of a office desktop (a SFF) from Lenovo- M90S. Should have went with the big tower and would have not had this issue.

The SFF doesn't have a Graphics Card. It is an office pc with i7-10700 and 68 GB of memory and 380W PSU. System Specs

It has a free 3.0 x16 PCIe and 3.0 x4 PCIe expansion slot and I want to add a GPU. However, given the size of the case, I cannot install a proper GPU. Only low profile GPU which is not helpful (the performance is not as good).

The PC is mostly used by significant other for office work. Me on the other hand would like to use it for gaming and thus add a GPU. The GPU doesn't need to run all the time and the gaming/sim racing rig will have a separate monitor altogether, so no issue there either. Also, the GPU will be used maybe 4-5 times a month.

The built in Intel UHD can power the standard monitors for office work.

My idea is this:

i) Use a PCIe Kickstand Kickstand
ii) Connect the PCIe cable to the empty slot in the PC. Use the PCIe Slot/Brack to run the cable.

My main issue is the power supply for the GPU. The 380W PSU that my system has can supply power to GTX 1650 Super without any issue.

But if I want to use a more powerful GPU, I will need more juice. I will need to use another power source. What are my option? Can I buy a 500-800 watt PSU and use the 6 pin and 8 pin connector, just to power up the GPU?

I understand the GPU would have a separate On/Off switch and a separate power supply and not be controlled through the PC's PSU and motherboard. Would this be a workable setup?

Just turn on the PC normally, then turn on the PSU for the GPU and connect the 3rd monitor to the GPU for gaming!

Or does the GPUs power need to be controlled through the motherboard?

I can put the external PSU and the GPU on a RIG, or find a way to put it on the gaming RIG and connect it to the PC when needed?

Any advise or suggestion would be greatly appreciated.
The only way to do this externally is via a thunderbolt external dock. The external dock enclosure will contain it's own PSU. I believe cooler master makes one.

https://www.amazon.com/Cooler-Master-MasterCase-Thunderbolt-Enclosure/dp/B08T63FV2C

I would not attempt this with a PCI Riser and extension cables. I mean technically you can. Miners do this for rigs when they use PCIe x1 expansion slots for mining. But for high performance gaming it is not recommended as these extension cables are not designed for long extension runs. Also if you pick the wrong power extension cable, fry your PS, fry your video card, or worst: Start a fire!
 

Eximo

Titan
Ambassador
If you don't care what it looks like, many options.

PCIe riser cables are quite common, and in use in high performance gaming PCs, not the 1x slot ones for mining, but full x16 width. MANY small form factor chassis come with them. One of those will let you relocate the GPU up to about 1 meter away at the maximum, but more typically about 25-40cm.

As you suggested, you can certainly run a second power supply. A little more complicated with a proprietary Lenovo, but doable.

Essentially the GPU just needs additional 12V power. So the 6 or 8 pin connectors from the additional power supply to the GPU. You need the two PSUs to share a ground connection so no voltage passes between them on the neutral wires, but this can be accomplished when you wire up the secondary PSU to start on power up of the other. (You need to gang the ground, standby, and power-on wires together)

For an enclosure you could just pick up a cheap ITX case to hold the PSU and graphics card.

Bespoke GPU enclosures exist, but are rather expensive.

The warnings about fires and wiring certainly are important to consider. If you aren't that familiar with PC power wiring or low voltage DC circuits, this might not be a good choice.



Better option. Move the Lenovo guts to a larger chassis, and get an adapter for a larger power supply.
 
Apr 27, 2021
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The only way to do this externally is via a thunderbolt external dock. The external dock enclosure will contain it's own PSU. I believe cooler master makes one.
Thanks for the advise. I looked at it and unfortunately my PC doesn't has a thunderbolt. It only has a USB-C Gen 3.2 which can only work up to 20 GBPS. But no thunderbolt input on my PC. Else would have just gone with that option.

If you don't care what it looks like, many options.

PCIe riser cables are quite common, and in use in high performance gaming PCs, not the 1x slot ones for mining, but full x16 width. MANY small form factor chassis come with them. One of those will let you relocate the GPU up to about 1 meter away at the maximum, but more typically about 25-40cm.

As you suggested, you can certainly run a second power supply. A little more complicated with a proprietary Lenovo, but doable.

Essentially the GPU just needs additional 12V power. So the 6 or 8 pin connectors from the additional power supply to the GPU. You need the two PSUs to share a ground connection so no voltage passes between them on the neutral wires, but this can be accomplished when you wire up the secondary PSU to start on power up of the other. (You need to gang the ground, standby, and power-on wires together)

For an enclosure you could just pick up a cheap ITX case to hold the PSU and graphics card.

Bespoke GPU enclosures exist, but are rather expensive.

The warnings about fires and wiring certainly are important to consider. If you aren't that familiar with PC power wiring or low voltage DC circuits, this might not be a good choice.

Better option. Move the Lenovo guts to a larger chassis, and get an adapter for a larger power supply.
Looks are not much of an issue. Thanks for the advise. I did some more research. I have a 380 Watt PSU which is 80 PLUS Platinum (seems a better quality one).

I found two GPU- 1650 Super (Recommended PSU 350W) and 1660 Super(Recommended PSU 450W) that I can connect to the MOBO using the riser/extension and instead of getting a PSU and make things complicated, just use the available 6pin or 8 pin from the PSU to power the GPU and call it a day.

I will try to create a cardboard size GPU and try to see if there will be a way I can stuff it in the case and still have descent cooling.

Thank you both for the advise. Will try to do as advised and in future if a more powerful GPU is needed, the best would be to get a new PC instead of going through all the trouble!
 
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Thanks for the advise. I looked at it and unfortunately my PC doesn't has a thunderbolt. It only has a USB-C Gen 3.2 which can only work up to 20 GBPS. But no thunderbolt input on my PC. Else would have just gone with that option.



Looks are not much of an issue. Thanks for the advise. I did some more research. I have a 380 Watt PSU which is 80 PLUS Platinum (seems a better quality one).

I found two GPU- 1650 Super (Recommended PSU 350W) and 1660 Super(Recommended PSU 450W) that I can connect to the MOBO using the riser/extension and instead of getting a PSU and make things complicated, just use the available 6pin or 8 pin from the PSU to power the GPU and call it a day.

I will try to create a cardboard size GPU and try to see if there will be a way I can stuff it in the case and still have descent cooling.

Thank you both for the advise. Will try to do as advised and in future if a more powerful GPU is needed, the best would be to get a new PC instead of going through all the trouble!
The USB standards committee took something that was painfully easy and really messed up the terminology to make it confusing.

USB-C Gen 3.2 is typically 10Gbps (gen 2), however can support 20Gbps (2x2).

Some USB-C Gen 3.2 have thunderbolt support built in. Thunderbolt 2 goes up to 20Gbps, while Thunderbolt 3 goes up to 40 Gbps

USB 3.2 explained: Making sense of current and confusing USB standards - CNET

Read your specs carefully. If you have a little lightening bolt above your USB port, you have thunderbolt support.

Thunderbolt (interface) - Wikipedia
 
Apr 27, 2021
5
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10
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The USB standards committee took something that was painfully easy and really messed up the terminology to make it confusing.

USB-C Gen 3.2 is typically 10Gbps (gen 2), however can support 20Gbps (2x2).

Some USB-C Gen 3.2 have thunderbolt support built in. Thunderbolt 2 goes up to 20Gbps, while Thunderbolt 3 goes up to 40 Gbps

USB 3.2 explained: Making sense of current and confusing USB standards - CNET

Read your specs carefully. If you have a little lightening bolt above your USB port, you have thunderbolt support.

Thunderbolt (interface) - Wikipedia
Thanks, I will go back and check it when I am home. AFAIK, no thunderbolt on this PC.
 

Karadjgne

Titan
Ambassador
I'd not try and seperate a gpu from a pc via riser card and power it with a seperate psu.
Risers are an extension of the pcie slot and contain power feeds from the motherboard, upto a supposed 75w. When you power a gpu seperately, the main power comes from psu #2 but primary power comes from psu #1, mixed internally inside the gpu.

That means literally the ground path and power path are both tied to the 380w psu from both psus and you run a severe risk of backfeed overloading the smaller psu. 1 good spike and psu #1 is toast, with the possibility of damage to the motherboard.

Best case scenario is buy a bigger, standard ATX case, move the guts over, cool that monster cpu right and use a correctly sized single psu to cover whatever workload you require.
 
Apr 27, 2021
5
0
10
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I'd not try and seperate a gpu from a pc via riser card and power it with a seperate psu.
Risers are an extension of the pcie slot and contain power feeds from the motherboard, upto a supposed 75w. When you power a gpu seperately, the main power comes from psu #2 but primary power comes from psu #1, mixed internally inside the gpu.

That means literally the ground path and power path are both tied to the 380w psu from both psus and you run a severe risk of backfeed overloading the smaller psu. 1 good spike and psu #1 is toast, with the possibility of damage to the motherboard.

Best case scenario is buy a bigger, standard ATX case, move the guts over, cool that monster cpu right and use a correctly sized single psu to cover whatever workload you require.
Good advise there and it makes sense.. will keep power from the PCs #1 psu.. and go from there.
 
Apr 27, 2021
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Better buy an external GPU enclosure with its own PSU and bridge. You can use it for different PC if needed as it's portable.
This would have been ideal. External GPU enclosures output are Thunderbolt 3. Which I do not have. Thus would not work for me.
 

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