multiple power supplies vs one large one?

[blazin8s]

lets say with a rig of 6 7970's just as an example

2x 750 watt gold psus = 200 + 1x500 watt psu for $50 = 250$

or

2x 1050 watt gold = 440$

Other than having less parts is there really a benefit to choosing the latter?  Is having more PSU's less power efficient?

I am thinking in terms of multiple rigs.  So saving 190 per rig can really add up.

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[jimmothy]

lets say with a rig of 6 7970's just as an example

2x 750 watt gold psus = 200 + 1x500 watt psu for $50 = 250$

or

2x 1050 watt gold = 440$

Other than having less parts is there really a benefit to choosing the latter?  Is having more PSU's less power efficient?

I am thinking in terms of multiple rigs.  So saving 190 per rig can really add up.

Would 4 x 500w work?

Also I've seen 1300w gold psu on newegg for 200

[crazyates]

Using multiple smaller PSUs work for big rigs like that, but there comes a point where you gotta back down.

Lets say a 6 GPU rig uses 1600W. You could get a 1600W PSU, but it's damn expensive, and you don't have much options. You could get a pair of 850W PSUs, and not only save money, but also give yourself some headroom.

No you could also buy 7x 400W PSUs, and put one PSU for each GPU and one PSU for the MB, but why would you want to run 7 PSUs?

I'd say work with the smallest number of PSUs you can afford, and if the price is close enough, go with the fewer PSU option. For 1000-1500W, I'd recommend two PSUs. For 1500-2000, you could go with 3, but I think it's easier to manage 2.

[YipYip]

Using multiple smaller PSUs work for big rigs like that, but there comes a point where you gotta back down.

Lets say a 6 GPU rig uses 1600W. You could get a 1600W PSU, but it's damn expensive, and you don't have much options. You could get a pair of 850W PSUs, and not only save money, but also give yourself some headroom.

No you could also buy 7x 400W PSUs, and put one PSU for each GPU and one PSU for the MB, but why would you want to run 7 PSUs?

I'd say work with the smallest number of PSUs you can afford, and if the price is close enough, go with the fewer PSU option. For 1000-1500W, I'd recommend two PSUs. For 1500-2000, you could go with 3, but I think it's easier to manage 2.

When u get into the industrialization of rigs ... go with 2 =x 1200 watt for 6 gpu setups that way both are in the happy zone of load

Use http://www.add2psu.com/ instaed of a paper clip ..lolz

6 & 7 card rigs the last thing u want to be messing with is power

[pjviitas]

I never had any luck with multiple psus...gpus don't get recognized properly

[jimmothy]

Using multiple smaller PSUs work for big rigs like that, but there comes a point where you gotta back down.

Lets say a 6 GPU rig uses 1600W. You could get a 1600W PSU, but it's damn expensive, and you don't have much options. You could get a pair of 850W PSUs, and not only save money, but also give yourself some headroom.

No you could also buy 7x 400W PSUs, and put one PSU for each GPU and one PSU for the MB, but why would you want to run 7 PSUs?

I'd say work with the smallest number of PSUs you can afford, and if the price is close enough, go with the fewer PSU option. For 1000-1500W, I'd recommend two PSUs. For 1500-2000, you could go with 3, but I think it's easier to manage 2.

When u get into the industrialization of rigs ... go with 2 =x 1200 watt for 6 gpu setups that way both are in the happy zone of load

Use http://www.add2psu.com/ instaed of a paper clip ..lolz

6 & 7 card rigs the last thing u want to be messing with is power

Do you know how many paperclips you can buy for $20??

In all seriousness is it really any sort of safety hazard to use the paperclip trick? For all I know (very little) add2psu is just a paperclip in a fancy container.

[gigica viteazu`]

First thing to take into account is the rating of the PSU.

I say go for multiple PSUs, if you use a single big PSU and it dies then your entire rig is out of business until you replace the broken part, meanwhile if you use multiple smaller PSUs you only have part of your rig out of business in case one of them dies.

[pjviitas]

I have tried the whole multiple PSU with paperclips and then running a jumper between all the green wires on the 24 pin power connector and I simply could not get it to work.

Is there something special that needs to be done?

[KWH]

I have tried the whole multiple PSU with paperclips and then running a jumper between all the green wires on the 24 pin power connector and I simply could not get it to work.

Is there something special that needs to be done?

Green and adjacent Black.

[HellDiverUK]

I have tried the whole multiple PSU with paperclips and then running a jumper between all the green wires on the 24 pin power connector and I simply could not get it to work.

Is there something special that needs to be done?

Some PSUs just don't work without some sort of load on the 5V line, especially older supplies.  Newer ones seem happy to just supply pure 12V, as very recent PCs use very, very little 5V (Haswell in particular).

[klondike_bar]

Do you know how many paperclips you can buy for $20??

In all seriousness is it really any sort of safety hazard to use the paperclip trick? For all I know (very little) add2psu is just a paperclip in a fancy container.

I would suggest a small (0.5") length of wire rather than a paperclip. same function, but less chance of it touching anything else. And then wrap it in a bit of electrical tape to make sure it stays put. I have 2 PSUs running that way at the moment

[pjviitas]

Do you know how many paperclips you can buy for $20??

In all seriousness is it really any sort of safety hazard to use the paperclip trick? For all I know (very little) add2psu is just a paperclip in a fancy container.

I would suggest a small (0.5") length of wire rather than a paperclip. same function, but less chance of it touching anything else. And then wrap it in a bit of electrical tape to make sure it stays put. I have 2 PSUs running that way at the moment

And you have no issues with the BIOS picking up the GPUs?

[klondike_bar]

Do you know how many paperclips you can buy for $20??

In all seriousness is it really any sort of safety hazard to use the paperclip trick? For all I know (very little) add2psu is just a paperclip in a fancy container.

I would suggest a small (0.5") length of wire rather than a paperclip. same function, but less chance of it touching anything else. And then wrap it in a bit of electrical tape to make sure it stays put. I have 2 PSUs running that way at the moment

And you have no issues with the BIOS picking up the GPUs?

I am running Antminers and a bifury system.

however, i see no reason why bios would notice/care how GPUs are powered. There is a slight delay in BIOS load/detection that surely allows for the time it takes for a GPU to receive power and boot up to a detectable state.

[pjviitas]

Do you know how many paperclips you can buy for $20??

In all seriousness is it really any sort of safety hazard to use the paperclip trick? For all I know (very little) add2psu is just a paperclip in a fancy container.

I would suggest a small (0.5") length of wire rather than a paperclip. same function, but less chance of it touching anything else. And then wrap it in a bit of electrical tape to make sure it stays put. I have 2 PSUs running that way at the moment

And you have no issues with the BIOS picking up the GPUs?

I am running Antminers and a bifury system.

however, i see no reason why bios would notice/care how GPUs are powered. There is a slight delay in BIOS load/detection that surely allows for the time it takes for a GPU to receive power and boot up to a detectable state.

That's what I thought until I tried it.

When I was troubleshooting this my setup was as follows:
-MOBO and GPU#1 on 850W PSU
-GPU#2 on 550W PSU#1 with Pin#16 PS_ON to ground
-GPU#3 on 550W PSU#2 with Pin#16 PS_ON to ground

When I fired everything up, GPU#2 and GPU#3 would spin for a bit like they where looking to be detected and then nothing while GPU#1 worked fine.

I tried tying the Pin#16 PS_ON for PSU#1 and PSU#2 to the 850W PSU to get everything to sync the PSU startup with no luck either.

I gave up and went to a single 1300W PSU and everything works totally problem free.

With this in mind, I would still like to get multiple PSU's working with GPU's so if anyone have any tips please let me know.

[klondike_bar]

^odd. perhaps there is some cross-feed between the different PSUs on the 12V line? I dont know much about how the 12V provided by the PCI slot and the 12V provided by the PCIe cables would interact, but i wouldnt imagine itd be a problem.

GPU forums may be more helpful on the issue, but perhaps turn on the secondary PSUs before the one connected to the mobo, maybe just half a second difference would make the cards visible to the BIOS or to windows

[pjviitas]

^odd. perhaps there is some cross-feed between the different PSUs on the 12V line? I dont know much about how the 12V provided by the PCI slot and the 12V provided by the PCIe cables would interact, but i wouldnt imagine itd be a problem.

GPU forums may be more helpful on the issue, but perhaps turn on the secondary PSUs before the one connected to the mobo, maybe just half a second difference would make the cards visible to the BIOS or to windows

From what I have read so far it is some kind of cross feed issue.

I think the biggest take-away on this issue becomes apparent when you look at all the how-to's for setting up a GPU mining rig...all of them are single PSU.  I am thinking there is a reason for this.

[gamersglory]

go with this it will save you money on power http://www.amazon.com/Corsair-Professional-Digital-Modular-Platinum/dp/B008Q7HUR0/ref=sr_1_1?s=pc&ie=UTF8&qid=1388534833&sr=1-1&keywords=corsair+power+supply plus 80 platinum 95% + efficiency