Topic: Advice on 2 PSU setup (Read 700 times)

I've never had a problem using 2 sata to molex adapters for risers on a single rail.

You're correct. and Ive been running my 1070 rigs in a similar manner (one psu powers all the risers, mobo, cpu, ssd and some gpus, the other does all gpus).



If I were you instead of loading 3 risers on one cable why not do it like this:

Use one molex cable per riser and youre good. Im assuming you got two cables (you will need to buy compatible risers or get the ver 009).
so that leaves 4 risers to power (now use 2 of the pcie cables to power 4 risers, use a splitter if need be).

To recap:
pcie cable: can do 2x6-pin risers.
molex cable: can do 1xmolex 4-pin riser
sata cable:throw that crap in the garbage especially when using amd cards that have a tendency to pull more from the slot on stock settings.

I run a wonky Frankenstein'd setup with a server psu powering the cards and a small psu for the board and two of the cards.

That said, I don't run a add2psu and don't really think it's that necessary. Save the $

Hi,

where did you get this info about add2psu? that the riser and gpu should be connected to the same gpu? from my research, risers should be powered by the same psu as the mobo... now I'm confused...

You should have been fine with 2 750w power supplied. That is wierd that it was cutting out because you can actually run 2 650 if properly undervolted with made efficient once you get the hang of it, but 750w is always the better way, but the 2 connector GPU's run more power. On EVGA 2 fan 1 plug 1070's will generally run 120-130W range at 85% power, but then the 2 plug will run 140-150W at 75% power. So in the end it really depends on your GPU's you are using. The ones i found to be the best if you can pick up at a great price are the 1070 hybrids. Run at 80% and pulling 130-140W with no real cooling required.

I picked up the 850w to pair it with the 750w. 1500w is about what you need for 8 gpu's. Once it's up and running, it's obviously drawing far less wattage. I'm at 1003w but trying to set it up with 2 x 750w was a pain in Windows and it would keep cutting out.

So for anyone reading this wondering about power. You can do with less wattage but you might not get past the config stage, that's where you need a lot more power. System is very stable anyway with more wattage.

Thanks for all the replies.

I have the entire system working great with 2 x 750w EVGA's gold supernova's fully modular. I have add2psu working properly. I have a mix of 1070's, they all take one connector except the Zotac which has the 6+8 connector. I thought for sure I was doing well with wattage since I'm pulling 940-960w, so adding another let's say even full power 150w which I won't, I'd be at 1100w from 1500w total which would only be 70-75% load. Do I need a more powerful PSU or am I good with these ones?

The issue is I'm finally ready to add an 8th card so I wanted to have the risers powered only 2 per cable but obviously it's not working since the one available sata slot (on PSU1) when used with 1 or 2 risers causes the system not to power on so I have to run 3 risers on the peripheral slot.

This is what I'm looking at:

2 x 750w PSU's.

PSU1: 3 x 1070's, 3 risers on one cable
PSU2: 64gb ssd, 4 x 1070's, had 4 risers on one cable but it was hot, split them up two a piece

Now I want to add the 8th card and I'm looking at only being able to put it on PSU2 and the riser would have to go on the cable with 2 already. Should this be okay or do I need to pick up an 850w to pair with my 750w?

all of the distributors or sold out (technically). kind of hard to explain and i probably can't get into details about it due to non disclosure agreements i have in place. if you are looking for large qty of gpu's i can easily supply you with those. ill send you a PM.

Yeah the Newegg card and Amazon card are both from synchrony. They are great and both offer 12 months no APR. When buying on Amazon, you can get 5% off too if you dont need the no APR. So if you buy $1000 worth on the card and plan on paying it off right away, it will only cost you $950. I use the Newegg card for no APR and the Amazon card for 5% off, and sometimes the no APR. Its great since Synchrony is a great credit card offering company and will give you nice high limits without an issue as long as you have a good range credit score. Sadly, i dont really have hook ups with any vendors on GPU's so i browse my systems periodically and buy at good prices. For example i purchase 2 8 1070 systems from Amazon last week, and just kept browsing an picked up 16 1070's for $385 each before my 5% off. After everything i was able to buy the 1070's for only $365 each, was also able to pick up 1080 ti's a few weeks ago after my 5% off for around 630-640 a unit. I have a retail license but it is in the Toys and Gaming industry which is my main business but never tried to find a distributor for graphics cards just use it to mostly save on taxes on Amazon.

now...using the newegg card is something i didnt think of doing. that is a good tip, i just hate holding balances on all my cc's i carry $0. but 12 months no apr sounds like a pretty good idea.

i havent had any issues with pricing between NE and Amazon and other sites i am using. I have distribution access to a lot of companies also, but they are all sold out and eta's are months out. i am able to bring in gpu's with no qty on 1 of my vendors, so that is a plus that i don't have to worry about the retail side of things when it comes to buying hardware.

anyway, thanks for the tip on that CC no apr thing. that's a good one, didnt even think about it.

I dont know exactly why you would state i told him the same thing. You said to use an add2psu which is a chip, i told him to use a dual psu cable which is a cable that links straight to the motherboard and use a surge protector to power it on and off. Those are 2 completely different things.

Also i dont know if you know how Newegg Price Match guarantee works. The item must have the price match badge on the listing to get Newegg to price match, which PSUs do not have this price match badge. It is rarely on items, and most of the time it is on an item they know they priced higher and is out of stock on many websites and cant keep stock. So if you view the Newegg listing you posted it does not have the price match, it is listing an 850w psu for $159.99, but if you go to Amazon the 850w PSU it is $139.99 free shipping. I actually purchased 4 of the 850w G3 units last week for $109.99 each, so i do know it drops to $110 often, while Newegg's price will stay the same. I have the business account on Newegg and a Business account on Amazon, and in all reality newegg discounts arent anything. $450 for a 1070 that is selling $385-400 on Amazon, etc. Not great, and the only reason i use Newegg at the same time is the Newegg Store card for 12 months no APR when i am purchasing more mining rigs and equipment. I dont have to worry about paying the rig off until i am already in the profit and have my ROI. I do the same thing on Amazon, but mostly use the 5% extra amazon gives you for buying it with their store card which is not calculated into these prices.

you gave him the same information i did except told him to go different places to get the stuff he needs and not get the stuff I am using, which is the right way to do it. Actually, newegg is cheaper then amazon. dont forget tax. unless you are in california, it is tax free sales and that can be pretty major when buying expensive stuff. so yes, use newegg. also use ebates to get cashback on your newegg purchases.

not sure what hombre above is talking about on NE price gauging, i haven't been price gauged by them, maybe it's because i buy in bulk on the business side, I am not sure.

and not knowing your current pricing on the PSU between newegg and amazon is important. the psu's on amazon are not $110, they haven't been for a very long time. use camel camel camel to see. Newegg also price matches Amazon as long as its shipped and sold by amazon. http://promotions.newegg.com/nepro/13-2430/index.html and again on top of that you most likely won't pay sales tax, and using ebates your getting money back...so yea, I would stick with newegg and just dig a little into the offers before being so quick to judge others setups

using 2 PSUs is fairly simple. all you need to coordinate between the two of them is either an electric switch where you plug a molex cable from the secondary PSU. or and ATX cable adapter for the same secondary PSU.

it is true that it is highly not suggested to use the same rail for more than 2 cards as what most likely will happen is that the connection in the PSU will simply melt down.
using sata to molex adapter should also be the last option since they might also melt, and  if you choose to go this route, do not connect more than 1 adaptor to one sata rail.
cheers.

Dont waste your time with a the add2psu adapter just use a dual psu cable https://www.amazon.com/PSU-Supply-24-Pin-Motherboard-Adapter/dp/B072JM7KVD/ref=sr_1_3?ie=UTF8&qid=1501654950&sr=8-3&keywords=dual+psu+adapter . How i make sure my 2 PSU power the same everytime is i connect my 2 PSU units to a 20 AMP capable Surge Protector, and use the on/off on the surge protector. Have used it that way for a long time no issues. Now 2 Sata Risers per PSU is recommended, and Cryptomined made a great video on how to hook up you 8 GPU rig to 2 PSU's its on youtube (8 GPU Mining Rig). I would recommend following his video if you are unsure how to hook up all the GPU's and Risers to the PSUs. Pretty much 4 risers will share 2 Sata plugs, and then the remaining 4 will have their own sata.

Also dont pick up your items on Newegg like others post. Newegg likes to raise their prices with demand and their PSU are expensive now. Go to Amazon.com and get a great price. 2 850w G3 PSU's gold were only $110 each when i purchased on Amazon. I think the 850w are only 110-120, while newegg is $150+.

Benny, here is how mine is setup. i run 8 1070 cards just fine.

2 EVGA 850 gold PSU - https://www.newegg.com/Product/Product.aspx?Item=N82E16817438018
1 add2psu adapter - http://www.add2psu.com/store/each

1st PSU runs the MB, SDD, 4 risers, 4 GPUs
2nd PSU runs 4 GPUs and 4 risers

With the add2psu you need to plug the motherboard cable from the PSU2 into the add2psu MB slot, then the molex cable from the PSU1 PERIF slot into the add2psu molex slot.

You need to know that the PSU that powers the riser MUST power the GPU on the same PSU to work with the add2psu adapter. What i mean is you don't want to have like...PSU1 powering a riser, then PSU2 powering the GPU in that riser being powered by PSU1. They MUST be powered by the same PSU.

What does the add2psu adapter do? It just allows you to power off and on the system @ the same time in sync format. If you don't use it, you can turn off the machine, but 1 PSU will stay on, or both, or it won't power down until you manually unplugged or hit the switch.

I do not know how many vga plugs your PSU has currently, but if it is like mine in the link above you should be ok with my above directions.

I would advise you to be very careful when using SATA connectors for your mining rig. SATA connectors cannot handle the current that molex connectors can, and when users weren't careful, they have melted and/or started fires. Pushing those connectors beyond their spec is generally a bad idea on a system that's being pegged 24/7.

If you pay close attention to how much power you're going to have running through them, you'll be okay. I have an old 7770 getting its 6-pin PCIe power from an adapter connected to a single SATA connector, and it's worked fine for years.

What kind of 1070s do you have? (Specifically, what kind of power connectors do they accept? How many 6/8 pin PCIe power connectors?) Do your powered risers use SATA, molex, or PCIe connectors?

Lastly, some more information about your power supplies might be helpful, just to get a better idea about what your cabling options are, since it sounds like you have modular PSUs.

Hey guys need some help here. I currently have 7 x 1070's hooked up to 2 EVGA 750w PSU's. Current power draw is 963w from the wall so I thought I was doing well and am considering addding an 8th card. After watching a Bits Be Trippin video, he says do not run more than 2 powered risers on the same cable due to over heating. I was running 3 per rail and one of my cables was indeed hot. So I tried splitting them up 2 a piece. On the PSU that plugs it the motherboard - I can't use the last SATA plug on the PSU to power the risers.  The computer won't turn on. The only thing that works is running three powered risers on one rail and my other power supply splits the remaining four cards with no issue.

Does anyone know if this is because the Sata port on the PSU can't be used to power the cards? Or do I need an 800w PSU to go along with the 750 if I plan on having 8 GPUS? Any input is appreciated, thanks!