I got a couple questions. I got 4 XFX RX 470 OC cards and am setting them up to crunch on a GB F2A88X-D3H Motherboard with an AMD A10-7890K with the Wraith Cooler.

Can I run these cards with a 725W power supply and the MB etc. It will be just for crunching, but it will be running 24/7.

If not, how can I sync two power supplies, one to power the MB and 1 card and the other to power the other 3 cards to turn on at the same time? These are setup in a caseless rig I made out of PVC, yeah I know but hey, cheap and cooling is easy :)

Any suggestions, I could just toss a switch onto the one PS and fire it up at the same time I turn the other one on, but I'd like to tie them together so when I turn the MB on it turns everything on at the same time. Yeah I could get a 1200W power supply, but I am trying to save cash here and it's kinda fun working on stuff like this.

Appreciate the help!

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Oh, these are the two power supplies I have:

https://www.amazon.com/Sentey-XPP725-HS-Computer-Desktop-Bearing/dp/B00SN6VN7W

This is the rig so far :)

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I found this, I am going to get one. HardOCP likes them and it looks simple enough.

http://www.add2psu.com/

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I think this CPU will be a little weak for 4 GPU`s.
It only has 2 modules / 4 threads.

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With each crime and every kindness we birth our future.

I think that a 750W PSU will be at best "marginal" with four GPUs - I do note that XFX are somewhat reluctant to declare the power needs of these cards, so I would guess they are at the higher of the single 8-pin connector, say 150-175W each, which puts the GPU demand at about 600-700W, add another 250-300 for the rest of the system and you are looking at the high side of 800W, possibly up to 1000W.

I would be very wary about using things like the "Add2PSU", that you have identified as many PSU are not deigned to be "paralleled up" to give you more power, however I believe there are PSUs that are designed to supply stacks of GPUs, but these are generally quite expensive as there is only a small market for them, so I've gone in the direction of high-power single 12v rail units.

Edit - I found a power demand figure for the base clock speed version (120w), so given this is an overclocked card I would add at least 10% power per 2% clock increase.

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

Greetings

You have two 750 watt PSU's on hand, why not try and source another MB and CPU combo, that you could pick up cheap 2nd hand on EBAY or AMAZON.

Thinking this might be a bit safer and also might not fry your GPU's, not a sparky but someone around here could verfiy this.

I am still running on LGA775 motherboards with INTEL quad cores.

Have fun and if you do figure it out, let us know how it goes.

Regards

Greetings

You have two 750 watt PSU's on hand, why not try and source another MB and CPU combo, that you could pick up cheap 2nd hand on EBAY or AMAZON.

Thinking this might be a bit safer and also might not fry your GPU's, not a sparky but someone around here could verfiy this.

I am still running on LGA775 motherboards with INTEL quad cores.

Have fun and if you do figure it out, let us know how it goes.

Regards

I was thinking of that as well. But right now, I can't even get the cards to process units. The system runs rock steady until I put work units into the GPU's and then I get in an eternal reboot loop. It leaves me just enough time, if I am fast enough, to suspend the GPU works units, in which the PC goes back to normal and doesn't reboot.

Going to try Windows and see how it works.

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For years now, I have known single rail PSUs to be the most reliable source of kitty juice.
Mostly PC Power and Cooling Silencer series. Only one failure in many years, and that was a pin on the main connector that burned up. Which they replaced under warranty. 7 of my 8 rigs are still running on the PCP&C PSUs I built them with many years ago.

The last PSU I bought was an EVGA 1300 G2, because PCP&C got bought out, I think.
Rock solid and a ten year warranty, if I recall correctly.
And I needed a power capacity increase due to upgrades on the rig, not that the old PSU had failed.
I still have it as a spare for lesser rigs.
As with most other things in life, you generally get what you pay for.

My advice has always been........
Never, ever, scrimp on the PSU. A marginal one can have you chasing your tail trying to find problems that would not exist if the power was clean and stable.

TRUST the kittyman.............I've been through, ages ago, trying to save a buck on the PSU.
But the best you can afford. Scrimp elsewhere if you must, but NOT on the PSU.
Once you take a rig that has been nothing but trouble and swapped everything out once or twice trying to figure it out, only to find that once you plug in a good solid GPU and the troubles all vanish?
That is a lesson not soon to be forgotten.

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"Freedom is just Chaos, with better lighting." Alan Dean Foster

For years now, I have known single rail PSUs to be the most reliable source of kitty juice.
Mostly PC Power and Cooling Silencer series. Only one failure in many years, and that was a pin on the main connector that burned up. Which they replaced under warranty. 7 of my 8 rigs are still running on the PCP&C PSUs I built them with many years ago.

The last PSU I bought was an EVGA 1300 G2, because PCP&C got bought out, I think.
Rock solid and a ten year warranty, if I recall correctly.
And I needed a power capacity increase due to upgrades on the rig, not that the old PSU had failed.
I still have it as a spare for lesser rigs.
As with most other things in life, you generally get what you pay for.

My advice has always been........
Never, ever, scrimp on the PSU. A marginal one can have you chasing your tail trying to find problems that would not exist if the power was clean and stable.

TRUST the kittyman.............I've been through, ages ago, trying to save a buck on the PSU.
But the best you can afford. Scrimp elsewhere if you must, but NOT on the PSU.
Once you take a rig that has been nothing but trouble and swapped everything out once or twice trying to figure it out, only to find that once you plug in a good solid GPU and the troubles all vanish?
That is a lesson not soon to be forgotten.

Yeah, I was trying to keep it cheap as I got these new for nothing. And for what it's worth I was trying to do this on a budget :) I run a 1200 PC Power and Cooling on my main rig and I agree, never had an issue. I just got one of the Silencer series, platinum 1200. I will put it in my system and take my other 1200 out and use it.

I believe the issue was the video cards, either they were defective, which I doubt, not 4 of them, or they were simply not compatible with the MB or Chip set on the MB. I even installed Windows 10 x64 and had the exact symptoms. As soon as I put a load on the video cards, Seti Units, or whatever, the system would simply reboot. So I returned them to Amazon and wrote the manufacturer XFX if they were compatible with that board. I will just use this rig as it is and use my old Gigabyte board.

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Hello
http://outervision.com/power-supply-calculator
http://www.coolermaster.com/power-supply-calculator/

Of course I suggest you calculate with a very little CPU, no any adds and one of your monster.
So you will have the PSU for one card.
Then again calculate with all with two GPU and add two times to global result the power
of second calculator.
If you PC runs 24/7, then multiply the final result by 1.3 (because the condensators suffers)

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I really like your setup. What pciexpress extender you using?
The add 2nd psu seems to work well. The nice thing is that can even turn on the second PSU for you.
http://www.ebay.ca/itm/2-pk-Dual-Triple-Multiple-add2PSU-Relay-Adapter-Power-Supply-Adapter-Connector-/361872887876?hash=item54414e1044:g:uUIAAOSw241YcDe8
Theres also "Fake" ones for much cheaper, but I never trust them

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Mitchell - the symptoms you are describing are very typical of a PSU that is way below what you need. Try running one GPU for a bit, make sure each GPU is working correctly in each slot. If you are trying to use extenders, check them all, in each slot with each GPU - this will take time, but you do need to know that all the "external" stuff is OK when running on its own before you stack four in on extenders. Next try with two GPUs, again testing all the combinations of GPU, slot and extender. Repeat again with three GPUs, and finally putting all four in. This will take time, so don't try to do it in a rush.

Over the years I've found the Coolmaster calculator to conservative by between 25% and 50%, so use with care!
The Outervision one doesn't understand recent equipment, so its not as useful today as it once was.

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

I think that a 750W PSU will be at best "marginal" with four GPUs - I do note that XFX are somewhat reluctant to declare the power needs of these cards, so I would guess they are at the higher of the single 8-pin connector, say 150-175W each

I know, older post and all, but perhaps that someone wants to know. The XFX 470s draw 110W. (source 1, source 2)

Other brands on Alternate's websites show the same draw for the 470.

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Mitchell - the symptoms you are describing are very typical of a PSU that is way below what you need. Try running one GPU for a bit, make sure each GPU is working correctly in each slot. If you are trying to use extenders, check them all, in each slot with each GPU - this will take time, but you do need to know that all the "external" stuff is OK when running on its own before you stack four in on extenders. Next try with two GPUs, again testing all the combinations of GPU, slot and extender. Repeat again with three GPUs, and finally putting all four in. This will take time, so don't try to do it in a rush.

Over the years I've found the Coolmaster calculator to conservative by between 25% and 50%, so use with care!
The Outervision one doesn't understand recent equipment, so its not as useful today as it once was.

I did. I found out it was a compatibility issue with the MB and the Cards. I couldn't even get the system to crunch using one GPU in a socket running Windows. So I determined it wasn't the video drivers for Linux. Then I determined it wasn't the PS. Then the OS (from Linux to Windows). Ran the cards in a slot instead of a PCI extender, so ruled the extenders out and lastly, I moved them to a new board / CPU combo and they worked. It's been a while since I have had hardware comparability issues, but that's why i stay away from AMD. I don't seem to encounter these issues with Intel at least not as often.

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