ePSU for 1080ti

[shutterangle]

Hi there, newbie here. I joined to post this thread. I've read through tons of threads here and learned a lot, and I've managed to get a 1080ti running in my 2009 MP 4,1 flashed to 5,1 with power from the built in connectors + a SATA port. It's working great! However, when it goes under VERY heavy load, it crashes the computer. Not a huge deal because that doesn't happen very often for me (video editing/colouring), but I'd like to prevent this in future if possible, so I'm considering hooking up a PSU for the card externally, and running the 2 8-pin connectors in through an open pci-e slot in the back. I'm not interested in the pixlas mod or any of the soldering stuff since I'm no good at this stuff.

I've seen the threads about jumping the motherboard connector so that the ePSU stays on all the time, but I've also seen in this thread that you can connect to the computer's power so that it detects when to turn it on and off. I'd like to attempt to do that if possible. In that thread it mentions using a molex to SATA connector... although if I'm not mistaken, that's because that particular PSU uses molex as the detection.

My question is, if I were to get a basic PSU like this one, which doesn't seem to me to have molex, would I be able to just connect one of its SATA connectors (assuming it has them..total newb here) to a drive bay for instance, and would it detect the power to turn it on and off?

 

[bsbeamer]

I'll give you the experience from a client's machine with GPUs in an external PCIe expander box:
Start with COLD everything.
Power on the external PCIe expander.
Let run fully and all components get up to speed (say 1 minute).
Power on Mac Pro tower.

If you do NOT follow that order, the GPUs (and other components) in the PCIe expander do not show up.

Would you run into this with a dedicated external PSU? Not 100% sure. From the reports I've followed over the years most follow an almost identical procedure.

 

[shutterangle]

I'll give you the experience from a client's machine with GPUs in an external PCIe expander box:
Start with COLD everything.
Power on the external PCIe expander.
Let run fully and all components get up to speed (say 1 minute).
Power on Mac Pro tower.

If you do NOT follow that order, the GPUs (and other components) in the PCIe expander do not show up.

Would you run into this with a dedicated external PSU? Not 100% sure. From the reports I've followed over the years most follow an almost identical procedure.

Yeah I figured that would be the case, but that's not super attractive to me so my question is whether there is a way to tie it into the tower so that I can leave the PSU on all the time, and have it boot up when the computer boots up, by some sort of connection?

 

[bsbeamer]

Unsure, just relaying my experience. Never seriously looked into external PSUs for my personal machine and always purchased GPUs that could be internally powered. Highly considered purchased PCIe expanders numerous times and ALL of them required powering on before the Mac Pro tower. All clients with external PCIe expanders or franken-rigs of cards power them up BEFORE their machines.

Good luck, maybe someone here has more info.

 

[abdyfranco]

Have you tried the Pixlas Mod? I think it can be useful to you without the need for an additional power source.

 

[shutterangle]

Have you tried the Pixlas Mod? I think it can be useful to you without the need for an additional power source.

I haven’t tried it, but am aware of it. Not super interested in doing it for a few reasons, but mostly because I suck at that sort of thing and would love just a plug and play solution.

 

[bsbeamer]

You are not going to find a "plug and play" solution for external PSU with automated on/off control for GPU usage without modifications of some kind. The MacPro was not designed to be easily configured this way. An easy "Secondary PSU Extension Jumper Cable" is not readily available to link over with one cable/wire/plug.

For as often as I turn my machine on/off (usually 1 per day max), I would just hookup the external PSU and turn it on before turning the machine on. It's not that big of a deal.

 

[shutterangle]

Okay great, thanks bsbeamer that's what I needed to hear. Somehow I got the impression that I might just be able to tie into the power from the computer and that would do it. Good to have that cleared up. I think I will do exactly what you've mentioned. Cheers