Topic: Powered Risers and SATA (Read 335 times)

2 is often TOO MANY, depending on the wiring and the specific PS model.

I NEVER put more than one riser on a Molex chain, and I don't use SATA chains at all.

Yeah only 2 powered risers on each rail! Molex or SATA. 2 is MAX.
I burned those modular cables on Gtx 1060 and rx 470/480

You have just pointed out WHY some folks have issues with SATA power on risers and others don't - cards VARY a lot on how much power they draw from the PCI-E bus and there's no way to predict it without actually trying the card model at the specific settings you plan to use it.

Also, a USB-type riser ITSELF uses a little power for the "voltage conversion" circuitry needed to provide the voltages OTHER THAN +12VDC that are used on the PCI-E bus and it's interface, so the actual draw on the +12VDC line could exceed the PCI-E rating for 75 watts power draw from the bus WITHOUT the actual GPU card exceeding the spec (and a few cards HAVE been shown to exceed the spec at least on peaks).


MOLEX connectors don't have this issue - they're rated for 156 watts - the limit THERE is the wiring TO the connector, like on PCI-E power connectors, but the wiring is pretty much always good for at least 84 watts per "molex chain" and often 120.


 Also, while the SATA chain might use a 6-pin connector like PCI-E uses, that does NOT mean it's an actual PCI-E connection powering the chain - EVGA in particular specifies it's SATA/Peripheral ports on the G2/P2/T2 series to handle 75 watts per port.
 Adaquate to power ONE riser, but more than one riser = LIKELY problems.

to me  the best way is plug it all into the psu with pcie cables including the Risers, i use nothing but Risers cards with PCIE plugs after some bad time with other plug types ....been doing that for a year with my own made up server PSU cables and break out boards i won't use ATX psu by i won't use ATX psu i mean the normal atx psu. .i use server psu's and Pico ATX Switch PSU's to power the mb an ssd plugged into the server psu with pcie cables on two 240 lines and we will finally have solar on my house by April so im gonna abuse the hell out of it. an put old miners i have laying around online for the fun of it.

 I have one rig with 4 GPU's using SATA for powering Risers, its a one to one rule, It didn't burn my house, nor destroy my GPU's, mining for more than a year already and still kicking.

Yeah, deffo. Depends on the setup. I did run 2 x 470s on the same sata for 6+ months, they were fine. Also I imagine it's down to the molex to sata adaptor quality, which is kinda hard to tell in advance...

I have succesfully used a single sata to power 2 risers.  I noticed the risers were running very hot, so I only power 1 riser per sata from the PSU.

Seems safer.  All video cards get the majority of their power from the supplemental power if they can.

bullshit, never use sata for powering risers. just in cause you want to burn your home or destroy your gpus

With 'normal' MBs I've always followed the 'one riser to SATA string' rule, and (touch much fucking wood) nothing has burned down . That said, them Onda boards have 3 molex and 3 sata for 8 gpus - so go figure that...

I received risers today, I'm planing to power them directly from the modular outputs of my PSU. One output for one riser.

I saw that some risers have 3 connectors. Is it safer to use molex to power riser? Does molex have the same limitation as SATA? 

I use the EVGA T2 & P2 series power supplies exclusively in my builds and have no issues or heat when running 3 SATA powered risers on a single chain.  I would stay under 3 on a single chain though... And please buy a quality PSU.

We have used SAta Power Connector for our rigs
but be carefully , connect the riser to different sata trees.

we had one rig which burned the sata rubber cable , if there are more tha 3 cards on one sata tree the cable went extremly hot

thanks patrick

Looks like you had a lucky escape. What's your improved setup? Are you now powering two risers per SATA cable or did you move away from SATA altogether? Out of interest, what type of GPU's were they?

Thanks in advance for any info

I can tell you from the first hand. I tried to power 3 gpus from 1 sata cable and i am not doing it again I fried the modular cables on the psu. Psu itself didn't die so I am still using it, but i got my lesson 

Thanks for the response. I've seen some horror stories with accompanying pictures but a lot seem to be doing exactly what you say to avoid, i.e. powering more than two risers with the one SATA cable and, especially worrisome, doing so with AMD cards which seem to draw more power from the board.

Like I say above, I wouldn't feel comfortable powering more than one Asus RX 570 Strix OC riser from the one PCIe SATA cable but I'm going to go ahead and allow myself to power two of my NVidia cards with each PCIe cable.  

What you said is 99% right. but don't worry, you can use SATA for powering your riser because your riser power will be combining with PCIe Power to handle your GPUs. But, don't use more than 2 SATA connector from one rail, it will be safe.

There's a lot of conflicting information regarding the safety, or lack thereof, of using SATA connections to power powered risers in a mining rig. Lots of threads give blanket 'yes' or 'no' answers to whether it's safe to do it. However, my research suggests that there is no one-size-fits-all answer.

My understanding is that each SATA connection can handle 54 watts - or 4.5 amps on a 12 volt connection.

Looking at the Tomshardware test results of power draw from the motherboard for something like an Asus RX 570 Strix OC, it appears that it'd be unsafe to use SATA at all (5 amps from motherboard on gaming settings).

However, looking at the results for my AORUS GTX 1080 Ti Xtreme, it only drew 3.2 amps from the motherboard on 'gaming' settings. It looks like we have no issues here and, in fact, significant leeway.

When we further look at the specs for the 6 pin PCIe connection powering the string of SATA connectors, it appears that it can handle 75 watts - or 6.25 amps on a 12 volt connection.

Given the above information, I feel that it should be safe to power two powered risers from each string of SATA connectors powered by a 6-pin PCIe cable. The gaming settings would result in two SATA connectors drawing 6.4 amps from a 6.25 amp rated cable - but my mining settings currently draw 10% less overall watts from the wall when compared to their gaming settings.

Am I looking at this correctly?