Advice regarding risers and GPUs

[Eternu]

Recently I got two  GTX 1070 G1 Gaming 8G GPUs, and bought 2 risers for them. With those risers I got SATA powering cables, so I connected them and everything worked fine... or so I thought. Luckily not long after I have discovered that those SATA powering cables are overheating. First I thought that those cables was of low quality and got new ones. But that didn't help. So I looked online for explanation and I have found some. Connecting those SATA was wrong choice, because they can not give enough power for risers if I understood correctly.

What I want to know is, is changing this SATA cables for 6-pin only solution or is there others, and if so which? Also I found out that powering risers from same line as you GPU is good choice, is that correct? Won't it took too much power from that line and leave GPU with less than sufficient power? Also recently I notice that Led lamp for power is blinking in random intervals, which indicate abnormal power supply and I'm not sure why. Because this GPUs requires 150W each and PSU that I have should have enough power to supply them both.

I have MasterWatt Lite 230V 700W PSU 80% certified.

EDIT: Sorry, forgot to mention. I used two separate SATA lines for powering those two risers. Also I have two separated lines of 8-pins for supplying GPUs.

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[xberg]

Don't connect 2 cards to the same SATA cable: SATA does not support such current.
Use SATA for one and Molex or 6 pin for the other card, or another SATA cable if your PSU came with 2 SATA cables.

[gt_addict]

Get yourself different risers. If you are only powering two risers then you can do that from one cable using 6pin connectors. Never use sata!  Then a dedicated cable for each gpu.

[Eternu]

Don't connect 2 cards to the same SATA cable: SATA does not support such current.
Use SATA for one and Molex or 6 pin for the other card, or another SATA cable if your PSU came with 2 SATA cables.

I forgot to mention, also I edited main post so that there is no confusion in the future. I used two different SATA lines to supply those two risers, I didn't put both on one. Supplying with two separated SATA cables is off.
So you say that I will not have issue if I supply riser on same power line as GPU? Also, wouldn't that be better than supplying it with Molex?

[Midcrypto]

Yea definitely don't use SATA power to run risers at all. Molex to 6 pin or 6 pin direct if you have extra with the PSU.

[CryptoPlay]

Im using Sata to feed riser and the PSU to feed 6 Vega 64.... no problem at all.

Its only a problem with low end cards that draw juice from the riser....
check the sata connector temp with your finger.

[Bigdrago]

I power gpu and riser with one 8pin from psu that splits into 8pin (to gpu) + 6pin (to riser).

[Eternu]

Im using Sata to feed riser and the PSU to feed 6 Vega 64.... no problem at all.

Its only a problem with low end cards that draw juice from the riser....
check the sata connector temp with your finger.

Well I'm not sure if its ok to call GTX1070 a low end card, but maybe you are right about it taking power from riser (I don't see why tho, because I power GPU with 8-pin power line). That would explain overheating, but on the other hand people say that SATA can't give enough power for risers. If you don't have the same problems like I have, than you are good... maybe.

I power gpu and riser with one 8pin from psu that splits into 8pin (to gpu) + 6pin (to riser).

Which PSU and GPU you have if its not a secret? Because I would rather supply riser from same line as GPU if its possible for me, than from molex.

[Piskeante]

the best combo for this is.

1 riser per sata cable
2 risers per Molex cable.

Why? because molex cable can provide up to 150W. that's why 2 risers per cable, because risers can use up to 75W each.

SAta provides no more than 54W per cable. Which should be safe enough to power a riser. it depends on what you are doing. It's very easy. If your card uses 130W powered with an 8 pin conector (which provides up to 150W), your riser with a SATA cable should do it's job just fine.

If you need to overclock to get the best out of your card while mining (not the case of ETH), with RX 580's you will be far from 150W of the 8 pin, and you may have problems with sata, even probably problems with 2 risers per molex, which would imply using only one Riser per molex cable.

[Bigdrago]

Im using Sata to feed riser and the PSU to feed 6 Vega 64.... no problem at all.

Its only a problem with low end cards that draw juice from the riser....
check the sata connector temp with your finger.

Well I'm not sure if its ok to call GTX1070 a low end card, but maybe you are right about it taking power from riser (I don't see why tho, because I power GPU with 8-pin power line). That would explain overheating, but on the other hand people say that SATA can't give enough power for risers. If you don't have the same problems like I have, than you are good... maybe.

I power gpu and riser with one 8pin from psu that splits into 8pin (to gpu) + 6pin (to riser).

Which PSU and GPU you have if its not a secret? Because I would rather supply riser from same line as GPU if its possible for me, than from molex.

Evga g2 1600W.
8pin from vga port that splits to 8pin and 6pin. Default cable from evga. I use 6pin extender to reach the riser. Each psu power 7 gpu.

[klepikolse]

the best combo for this is.

1 riser per sata cable
2 risers per Molex cable.

Why? because molex cable can provide up to 150W. that's why 2 risers per cable, because risers can use up to 75W each.

SAta provides no more than 54W per cable. Which should be safe enough to power a riser. it depends on what you are doing. It's very easy. If your card uses 130W powered with an 8 pin conector (which provides up to 150W), your riser with a SATA cable should do it's job just fine.

If you need to overclock to get the best out of your card while mining (not the case of ETH), with RX 580's you will be far from 150W of the 8 pin, and you may have problems with sata, even probably problems with 2 risers per molex, which would imply using only one Riser per molex cable.

So the cards are using power from 8pin and 6 pin cables first, and if that isnt enough, they are getting some from the PCI slot so that they dont overload the motherboard (as they were originally designed to be in MB slots)? Is that true?

[Eternu]

So the cards are using power from 8pin and 6 pin cables first, and if that isnt enough, they are getting some from the PCI slot so that they dont overload the motherboard (as they were originally designed to be in MB slots)? Is that true?

That would explain that blinking led lamp for abnormal power use in my case, if its true. But 8-pin powering line should be enough for supplying GTX 1070 which require 150w? Also if that is true, that would also explain my problem of overheating riser cables.

[Eternu]

the best combo for this is.

1 riser per sata cable
2 risers per Molex cable.

Why? because molex cable can provide up to 150W. that's why 2 risers per cable, because risers can use up to 75W each.

SAta provides no more than 54W per cable. Which should be safe enough to power a riser. it depends on what you are doing. It's very easy. If your card uses 130W powered with an 8 pin conector (which provides up to 150W), your riser with a SATA cable should do it's job just fine.

If you need to overclock to get the best out of your card while mining (not the case of ETH), with RX 580's you will be far from 150W of the 8 pin, and you may have problems with sata, even probably problems with 2 risers per molex, which would imply using only one Riser per molex cable.

This is really helpful, I guess only option that I have in this moment is to use Molex as supply line for risers. I guess that with what I'm doing 2 risers on one Molex should be just fine.

I would like to thank you all, for all the tips you gave me and you support. I will leave this topic open for a day more, maybe there is something more that I should know or directly connected to my problem.

Thank you all!

[jillscarbrough]

From my past discussions on another thread, I found a few things about this kind of problems.

1.We have zero control which would be drawn first by card, PCIe bus or PCIe connector. It may be was done by card's power management and depends on brands (manufacturers).

2.One sata (rail) for riser power, sound fine but not safer enough, related to point one. So better to use molex or 6pins.

3.We also need to know our PSU technical data itself to decide power scheme. But with two cards only, not really needed.

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And about your other question.
"Also I found out that powering risers from same line as your GPU is good choice, is that correct?"

It may referring to dual-PSU or more uses. GPU and risers powered by the same PSU.

[Ciscopro2000]

From what I understand, sata cables cannot provide enough power to support multiple risers.  You can use 1 sata cable per 1 riser.  But I chose to use either 6 pin pcie or molex connectors for my risers.  Those connectors support higher power usage. 

[Claudyah]

for GPUs I suggest GUIMiner and OpenCL that are compatible with graphics cards. When GUIMiner is first run, the software will automatically try to detect OpenCL available. If it is not found, you can still mine using the CPU.

[Eternu]

I got necessary information that I needed to solve my problem, so to stop further spam I will lock this thread. If someone have some crucial information that I need to know, feel free to send me PM.

Thank you all for helping.