[SOLVED] Running a GPU externally

[Semilanceata]

I've been considering ways to get a powerful GPU running in a small form factor HP with a 240W PSU.

The only way I can think of, would be to buy a secondary power supply to the card and have the card sit externally to the case, and to buy some kind of PCIE extension cable to allow the card to sit outside the case.


So I guess my questions would be,
1: Is there a power supply that would only supply power to the card when needed, (so as not to require having to power on two sources in unison when booting the PC (and off again)?
2: Any recommendations on a good PCIE extension which will retain the full speed?
3: Will this work theoretically? (Any bottlenecks I may be missing, HP mobo perhaps?)

Thanks in adv.

 

[QwerkyPengwen]

you can always jimmy rig something to be external.

as for dynamic power, that won't work because if you have the GPU plugged into the system then you have to plug the video cable into the GPU. End of story.
Which means that turning power off to the GPU would result on no display, or you having to always switch the cable out to the integrated graphics output on the motherboard, and then unplug the GPU from the motherboard everytime you don't want to supply power to the GPU to use it for something like gaming, and that all in all seems like a huge pain in the butt to me.

And to top it all off, if you basically plan to have an external GPU with a PCIe ribbon cable going into it, that means you won't have the side panel on at all.

And if that's the case, then just get a regular power supply with enough wattage and the right cables to power everything and then plug the GPU directly into the motherboard.

Since you won't have the side panel on either way, the PSU can then be external and you won't have to worry about the GPU being skinny enough to fit within the system due to the fact that the side panel won't be on anyways.

It'll look kind of open case frankenstein with the PSU outside the case and all the cables going into it from the open side panel, but would look better than a frankenstein system with the GPU external as well as a power supply, and would be a hell of a lot more practical until you can get some more money saved up to buy a proper sized PC case, and then just move everything into that.

 

[USAFRet]

A small case PC with an external GPU and associated power supply is no longer a small case PC.

Just put it all in a case that will fit, along with a proper PSU.

 

[justin.m.beauvais]

I'm going to start with #3. Theoretically, this is a doable idea. However, you have to consider the specs of your machine when selecting your GPU. If we are talking about doing this with a system with a Haswell or earlier i5 (or way worse an i3) your performance is going to be limited in the first place by the CPU. If you planned on anything more than an RTX 2060 you'll almost never see the GPU's full performance (may as well say never for an i3). The performance aspect is kinda a landmine.

Then there is the physical issue. First, there are jumpers that exist to power on more than one PSU from a single motherboard. The problem is that MOST of them are ATX, and sometimes those pre-built systems use proprietary connections. If you can get past that point you'll need a place to mount the GPU that has clean air and no risk of being bumped or having things dropped on it. PCI-E extender cables are generally ok if they are from a reputable brand.

Honestly this would be a fun project, but for a daily driver gaming machine, I'd never do it. Too many things that can go wrong and too little to be gained. You aren't going to be able to use a very powerful GPU with the generally weak CPUs that they put into these SFF systems, and what you can use will likely not be worth the trouble.

I'd recommend just getting a GPU that will work in it like a small form factor GT 1030. That should run most games at low settings 1080p. If you absolutely need more performance then you're going to need a case to fit it in, and your SFF hardware may not fit properly in a proper case.

 

[Semilanceata]

I'm going to start with #3. Theoretically, this is a doable idea. However, you have to consider the specs of your machine when selecting your GPU. If we are talking about doing this with a system with a Haswell or earlier i5 (or way worse an i3) your performance is going to be limited in the first place by the CPU. If you planned on anything more than an RTX 2060 you'll almost never see the GPU's full performance (may as well say never for an i3). The performance aspect is kinda a landmine.

Then there is the physical issue. First, there are jumpers that exist to power on more than one PSU from a single motherboard. The problem is that MOST of them are ATX, and sometimes those pre-built systems use proprietary connections. If you can get past that point you'll need a place to mount the GPU that has clean air and no risk of being bumped or having things dropped on it. PCI-E extender cables are generally ok if they are from a reputable brand.

Honestly this would be a fun project, but for a daily driver gaming machine, I'd never do it. Too many things that can go wrong and too little to be gained. You aren't going to be able to use a very powerful GPU with the generally weak CPUs that they put into these SFF systems, and what you can use will likely not be worth the trouble.

I'd recommend just getting a GPU that will work in it like a small form factor GT 1030. That should run most games at low settings 1080p. If you absolutely need more performance then you're going to need a case to fit it in, and your SFF hardware may not fit properly in a proper case.

It's an i7 4770, I'm running a 1050 Ti in it at the moment with no issues and 16GB corsair vengeance, but I want to try and push the graphics a little further. I have a desk enclosure to fit a more powerful card + extra power supply so space isn't too much of an issue, I'll be leaving the side (top in this case) panel on for this reason, and hopefully running the PCIE extension through the hole in the back and having the other components sitting in the desk space.
Yeah it'd look weird to have the organs hanging out, but the PC is out of sight anyway.

As you've stated, It's the proprietary HP PSU that concerns me here.
I'm not sure of a way I could link the 2 PSU's to both power on from a single switch for this reason.
As long as it's do-able though, I think it's probably worth it with this CPU?

 

[justin.m.beauvais]

It's an i7 4770, I'm running a 1050 Ti in it at the moment with no issues and 16GB corsair vengeance, but I want to try and push the graphics a little further. I have a desk enclosure to fit a more powerful card + extra power supply so space isn't too much of an issue, I'll be leaving the side (top in this case) panel on for this reason, and hopefully running the PCIE extension through the hole in the back and having the other components sitting in the desk space.
Yeah it'd look weird to have the organs hanging out, but the PC is out of sight anyway.

As you've stated, It's the proprietary HP PSU that concerns me here.
I'm not sure of a way I could link the 2 PSU's to both power on from a single switch for this reason.
As long as it's do-able though, I think it's probably worth it with this CPU?

Power is going to be your enemy here then. Powering up has to be synchronized to an extent that I don't know if a linked power switch will work. Does the external enclosure have a soft power switch? As in, you press it for a momentary connection and it energizes the PSU. If that was the case I'd see if you could get a similar switch with 4 wires, two on each side, connect one pair to the motherboard power headers and the other to the power connection on the external box. That is really the only way I can see this working.