I tried to find ways of using less power from the PCIe slot however it uses the same amount of power whether you are ETH only mining, ETH+SIA dual mining, or even when its undervolted to like 0.8V running at 1000 engine clock. IT always uses about 4.5-5.0 AMPS of current so like 55watts.
The riser only powers the +12V. The +3V comes from the motherboard since its only like 1 Watt, the +5V is never used in any GPUs only SATA harddrives. The riser just uses the +12V and GND.
I did some research on the subject and this is what I found:
1. According to two different sources, molex connector (each) can deliver either 96W or 60W. It does not really matter since if 55W is being used, it satisfies the requirement. how many molex connectors on the same cord could be utilized? I believe that the PSU end of the cable is rated for 150W, but i could not find direct reliable source for that info. If true, it basically means that two molex connectors on the same 'string' could be used, but three are too many (above 150W). 2. According to a source (playtool, see below) four wired 15 pin SATA connector can handle 54W. Since it is close to 55W mentioned, i think that it still could be used (with caution) as 55W number might be within the measurement error (could be be 54+/- 1). Probably 2 connectors on the same string can be utilized, three are above 150W and should not be used. 3. Floppy disk connector (see pictures in playtool link) can only handle 36W. This one is used in narrow risers. NOT to be used in cards that draw 55W from the riser!!!. I have used it so far ONLY on Sapphire RX 470 4gb OC card (platinum, NOT nitro), which draws just 85-95W total and for that card only it appears to be OK and connector is not overheating. Going forward, I will probably not use it on anything else, but these cards, if any.
Caveat/Disclaimer: I only tested my setups with genoil's. Maybe claymore is pushing power up and it would be too much.
I did some research on the subject and this is what I found:
1. According to two different sources, molex connector (each) can deliver either 96W or 60W. It does not really matter since if 55W is being used, it satisfies the requirement. how many molex connectors on the same cord could be utilized? I believe that the PSU end of the cable is rated for 150W, but i could not find direct reliable source for that info. If true, it basically means that two molex connectors on the same 'string' could be used, but three maybe too many. 2. According to a source (see below) four wired 15 pin SATA connector can handle 54W. Since it is close to 55W mentioned, i think that it still could be used (with caution) as 55W number might be within the measurement error (could be be 54+/- 1). Probably 2 connectors on the same string can be utilized, three are above 150W and should not be used. 3. Floppy disk connector (see pictures in playtool link) can only handle 36W. This one is used in narrow risers. NOT to be used in cards that draw 55W from the riser!!!. I have used it so far ONLY on Sapphire RX 470 4gb OC card (platinum, NOT nitro), which draws just 85-95W total and for that card only it appears to be OK and connector is not overheating. Going forward, I will probably not use it on anything else, but these cards, if any.
Caveat/Disclaimer: I only tested my setups with genoil's. Maybe claymore is pushing power up and it would be too much.
I agree with the article however the problem isn't the rail its the connectors.
The molex -> SATA you get with those USB risers are bad quality and melt, search for a Youtube video somewhere.
Also those Molex connectors are usually meant to be connected/disconnect maybe 3-4 times throughout its lifetime, I had most of my PSUs since the Litecoin mining days, the female end of the Molex are all very loose.
If you are concerned just test with your hand or tongue and see if its burning hot, if not then just leave it.
The riser only powers the +12V. The +3V comes from the motherboard since its only like 1 Watt, the +5V is never used in any GPUs only SATA harddrives. The riser just uses the +12V and GND.
Nonono...
Neither 12V or 3.3V comes from the mobo if you use USB risers.
Take a look at any USB riser. There is a 1084LM 3.3V voltage regulator on all of them that converts 5V from the molex to 3.3V. So you DO NEED 5V on USB riser! But that is only 1-2W per card, so you can use your whatever weak primary PSU 5V line for that. And you only need to take the 12V from the secondary strong PSU.
On ribbon risers the 3.3V comes directly from the mobo, so you only have to care about 12V then.
I already asked in another topic if anyone tried feeding the 1084 regulator IC also from 12V. Because it is possible, but the dissipated heat would be 3 times more compared to the 5V->3.3V conversion. I swear Im gonna do a test sometimes soon. If the IC goes above 65C then it's a no go and I have to use the 5V line from my primary PSU and only feed the 12V from my secondary server PSU.
I believe that the PSU end of the cable is rated for 150W, but i could not find direct reliable source for that info.
Yes, a high quality minifit terminal (used in PCI-E power conns) can handle 13A continously, that is ~150W at 12V. But they don't use that on ATX PSUs They use the common type terminal that is OK up to 9Amps so about 110W.
Basically what I mentioned earlier that I use DIY 6pin -> 3 x molex 12V converter cables is proven to be good by calculation. Way within safety margin.
The riser only powers the +12V. The +3V comes from the motherboard since its only like 1 Watt, the +5V is never used in any GPUs only SATA harddrives. The riser just uses the +12V and GND.
Nonono...
Neither 12V or 3.3V comes from the mobo if you use USB risers.
Take a look at any USB riser. There is a 1084LM 3.3V voltage regulator on all of them that converts 5V from the molex to 3.3V. So you DO NEED 5V on USB riser! But that is only 1-2W per card, so you can use your whatever weak primary PSU 5V line for that. And you only need to take the 12V from the secondary strong PSU.
On ribbon risers the 3.3V comes directly from the mobo, so you only have to care about 12V then.
I already asked in another topic if anyone tried feeding the 1084 regulator IC also from 12V. Because it is possible, but the dissipated heat would be 3 times more compared to the 5V->3.3V conversion. I swear Im gonna do a test sometimes soon. If the IC goes above 65C then it's a no go and I have to use the 5V line from my primary PSU and only feed the 12V from my secondary server PSU.
I never used USB risers so I never knew that. In that case you need to connect a SATA connector for the +5V and GND and the PCIe for the +12V and GND. Alot more hacking involved.
@adaseb You don't need the sata conn. In your case just take the original molex connectors on the psu and replace the 12V line with your adapter. The other 3 wires can be left as they are.
But of course if you run out of molexes you can use the sata connectors of your psu for the 5v with the sata -> molex adapters that you got along with the usb riser Nothing gets wasted at the end;)
You can power at least 6 usb risers with one atx psu this way. And you dont have to cut anything on the psu wires, just pull out the 12v pins of the molexes. You can do that with a narrow screwdriver. No permanent mods on the psu cables that way.
Gonna draw it if i have time. It is much easier to get it.
I'm dual mining ETH/SIA on a 480 devil (non-ref card) rig with 2 risers connected per molex string (direct molex connection to riser, not using those molex to SATA adapters). OC and UV, and not having any issues so far.
Take a look at any USB riser. There is a 1084LM 3.3V voltage regulator on all of them that converts 5V from the molex to 3.3V. So you DO NEED 5V on USB riser! But that is only 1-2W per card, so you can use your whatever weak primary PSU 5V line for that. And you only need to take the 12V from the secondary strong PSU
@restless but also have to consider the dissipated heat that is 3 times more if the input is 12v. That ic is not a switching type. So it very likely overheats. But we should try it.
guys im building right now my 1st mining rig, and reading this you got me really worried...
my rig is:
Gigabyte AM3+ AMD 970 SATA 6Gbps USB 3.0 ATX AM3+ Socket DDR3 1600 Motherboards (GA-970A-DS3P)
AMD FX 4-Core Black Edition FX-4300, FD4300WMHKBOX
Electop PCI E Express 1X to 16X Riser Card USB 3.0 Extender Cable with Power
and 4 of ASUS ROG STRIX Radeon Rx 470 4GB OC Edition AMD Graphics Card with DP 1.4 HDMI 2.0 (STRIX-RX470-O4G-GAMING)
I connected only 1 card on the 1 sata string, now ill connect the 2nd card on a separate sata string, but im reading this post and dont know what to do!
i got 3 separated sata cable + 1 perif port on the psu, so i could only connect 4 cards?
I was thinking the CPU2 connector is probably a great place to source more +12v and ground. Many PSUs offer one, yet they are only really used for server/workstation boards.
That provides four 12v and four grounds, all using 18awg wire and a solid 8-pin connector on PSU side, should be plenty for a pair of risers. My plan was to solder direct to the risers, then use a SATA adapter with only 5v connected My only concern is... should I be providing the second ground wire for the 5v from the SATA, or soldered directly along with the +12v and ground?
all grounds are connected together on the card, so it is OK, even if there is no ground at all for the riser's molex connector. One is recommended to be safe tho.
I believe that the PSU end of the cable is rated for 150W, but i could not find direct reliable source for that info.
Yes, a high quality minifit terminal (used in PCI-E power conns) can handle 13A continously, that is ~150W at 12V. But they don't use that on ATX PSUs They use the common type terminal that is OK up to 9Amps so about 110W.
Basically what I mentioned earlier that I use DIY 6pin -> 3 x molex 12V converter cables is proven to be good by calculation. Way within safety margin.
Which cable is that? cause my evga psu only have 1 perif1 output with 3 molex (ive read on this forum not to connect more than 2 video cards on the same cable), so im stuck? cause i cant connect the 3 risers for my 470s?
Unfortunately the PCIe Slot power is at least 5Amps or so for the 470/480. Some of the 6 pin 480 even use much more than 5 Amps. You can't power too many of them with the daisy chain Molex and especially the SATA connectors. Even the 8 pin 470s draw around 5 Amps from the slot.
If you have the space, best would be to install NO MORE THAN 1 of your 470/480 directly onto the motherboard.
I would avoid using any SATA connectors to power any of the 470/480 GPUs. They draw at least 60 watts and those SATA connectors are generally used for hard drives which draw about 5 watts on average.
I wouldn't use any more than 1 of the Molex connectors to power any 470/480. Usually a PSU has 2 sets of these (6 molex in total) so you can power 2 GPUS from each seperate chain.
The best method would be as follows. Usually most PSUs have 2x 6+2pin on each chain such as follows.
You would plug in one of those to your 470/480 #1 connection and the other would always be unused. Since the length wouldn't reach the next card. So you would buy a PCIe extension cable such as below
Plug in the unused PCIe #2 connector to this extension and splice the other end +12V and GND directly onto your Risers power.
This way you could run any number of high power 480s and overclock them to the max and you would never have any melt since the PCIe has plenty of power and is a higher gauge.
can you give me any advise how to rewire the molex? when you said splice i didnt get it, sorry
According to your image, i should use 2 black wires from the extesion and 1 yellow wire, and make a 4 pin molex that way?
Thanks, ill really appreciate some further instructions
Wierd I guess that I've NEVER had any melted cables from using 2-3 risers on 1 molex or sata chain. I use only good quality EVGA power supplies though, no cheap crap. maybe that's why.
You mean running 3x 2xx or 3xx series cards on one chain, right? Try running 3 470/480 on one molex chain and see what happens.
It is not trial error, it's the laws of physics. 3 * 70W => 210W on ONE 18AWG molex 12V wire. That is 17Amps on a 18AWG wire that can handle 10Amps max. For a few minutes it may work until it warms up enough to start melting the connector housing and burning the dust in the air onto the metal connector. I've seen this at least 50 times from my customers bringing in the burnt cables and PSUs for repair.
You mean running 3x 2xx or 3xx series cards on one chain, right? Try running 3 470/480 on one molex chain and see what happens.
It is not trial error, it's the laws of physics. 3 * 70W => 210W on ONE 18AWG molex 12V wire. That is 17Amps on a 18AWG wire that can handle 10Amps max. For a few minutes it may work until it warms up enough to start melting the connector housing and burning the dust in the air onto the metal connector. I've seen this at least 50 times from my customers bringing in the burnt cables and PSUs for repair.
will try your way for my 4 rig with 470 (4)
I use evga psu, and they say you can use the sata output from the psu to connect molex cables and viceversa, and i started a ticket on their website and they send me 2 string of molex cables for free when i ask about where i could buy more molex cables for my psu
Comments
A PCI-E 6 pin connector has 3x12V wires. It has zero 5V lines.
While Molex has one 12V (yellow) and one 5V (red) wire
So what about the 5V one, can you just ignore that? Will a powered riser work without it?
1. According to two different sources, molex connector (each) can deliver either 96W or 60W. It does not really matter since if 55W is being used, it satisfies the requirement.
how many molex connectors on the same cord could be utilized? I believe that the PSU end of the cable is rated for 150W, but i could not find direct reliable source for that info.
If true, it basically means that two molex connectors on the same 'string' could be used, but three are too many (above 150W).
2. According to a source (playtool, see below) four wired 15 pin SATA connector can handle 54W. Since it is close to 55W mentioned, i think that it still could be used (with caution) as 55W number might be within the measurement error (could be be 54+/- 1). Probably 2 connectors on the same string can be utilized, three are above 150W and should not be used.
3. Floppy disk connector (see pictures in playtool link) can only handle 36W. This one is used in narrow risers. NOT to be used in cards that draw 55W from the riser!!!. I have used it so far ONLY on Sapphire RX 470 4gb OC card (platinum, NOT nitro), which draws just 85-95W total and for that card only it appears to be OK and connector is not overheating. Going forward, I will probably not use it on anything else, but these cards, if any.
Caveat/Disclaimer: I only tested my setups with genoil's. Maybe claymore is pushing power up and it would be too much.
Sources:
http://www.playtool.com/pages/psuconnectors/connectors.html
http://www.overclock.net/a/gpu-and-cpu-power-connections
https://en.wikipedia.org/wiki/Molex_connector#Disk_drive_connector_.28Molex_8981_Series_Power_Connector.29
https://en.wikipedia.org/wiki/Serial_ATA
The molex -> SATA you get with those USB risers are bad quality and melt, search for a Youtube video somewhere.
Also those Molex connectors are usually meant to be connected/disconnect maybe 3-4 times throughout its lifetime, I had most of my PSUs since the Litecoin mining days, the female end of the Molex are all very loose.
If you are concerned just test with your hand or tongue and see if its burning hot, if not then just leave it.
Neither 12V or 3.3V comes from the mobo if you use USB risers.
Take a look at any USB riser.
There is a 1084LM 3.3V voltage regulator on all of them that converts 5V from the molex to 3.3V.
So you DO NEED 5V on USB riser! But that is only 1-2W per card, so you can use your whatever weak primary PSU 5V line for that. And you only need to take the 12V from the secondary strong PSU.
On ribbon risers the 3.3V comes directly from the mobo, so you only have to care about 12V then.
I already asked in another topic if anyone tried feeding the 1084 regulator IC also from 12V.
Because it is possible, but the dissipated heat would be 3 times more compared to the 5V->3.3V conversion.
I swear Im gonna do a test sometimes soon. If the IC goes above 65C then it's a no go and I have to use the 5V line from my primary PSU and only feed the 12V from my secondary server PSU.
But they don't use that on ATX PSUs
They use the common type terminal that is OK up to 9Amps so about 110W.
Basically what I mentioned earlier that I use DIY 6pin -> 3 x molex 12V converter cables is proven to be good by calculation. Way within safety margin.
You don't need the sata conn.
In your case just take the original molex connectors on the psu and replace the 12V line with your adapter. The other 3 wires can be left as they are.
But of course if you run out of molexes you can use the sata connectors of your psu for the 5v with the sata -> molex adapters that you got along with the usb riser
Nothing gets wasted at the end;)
You can power at least 6 usb risers with one atx psu this way. And you dont have to cut anything on the psu wires, just pull out the 12v pins of the molexes. You can do that with a narrow screwdriver.
No permanent mods on the psu cables that way.
Gonna draw it if i have time. It is much easier to get it.
There is a 1084LM 3.3V voltage regulator on all of them that converts 5V from the molex to 3.3V.
So you DO NEED 5V on USB riser! But that is only 1-2W per card, so you can use your whatever weak primary PSU 5V line for that. And you only need to take the 12V from the secondary strong PSU
That's exactly what I did! ^^
A quick look at http://www.ti.com/lit/ds/symlink/lm1084.pdf , shows no requirement Vin to be 5V, so I guess the simplest way will be to get it from 12V
A quick look at http://www.ti.com/lit/ds/symlink/lm1084.pdf , shows no requirement Vin to be 5V, so I guess the simplest way will be to get it from 12V
So it very likely overheats. But we should try it.
my rig is:
Gigabyte AM3+ AMD 970 SATA 6Gbps USB 3.0 ATX AM3+ Socket DDR3 1600 Motherboards (GA-970A-DS3P)
AMD FX 4-Core Black Edition FX-4300, FD4300WMHKBOX
Electop PCI E Express 1X to 16X Riser Card USB 3.0 Extender Cable with Power
and 4 of ASUS ROG STRIX Radeon Rx 470 4GB OC Edition AMD Graphics Card with DP 1.4 HDMI 2.0 (STRIX-RX470-O4G-GAMING)
I connected only 1 card on the 1 sata string, now ill connect the 2nd card on a separate sata string, but im reading this post and dont know what to do!
i got 3 separated sata cable + 1 perif port on the psu, so i could only connect 4 cards?
Many PSUs offer one, yet they are only really used for server/workstation boards.
That provides four 12v and four grounds, all using 18awg wire and a solid 8-pin connector on PSU side, should be plenty for a pair of risers.
My plan was to solder direct to the risers, then use a SATA adapter with only 5v connected
My only concern is... should I be providing the second ground wire for the 5v from the SATA, or soldered directly along with the +12v and ground?
One is recommended to be safe tho.
How you connect your for example 6 RX 480/RX470 cards on this mobo?
According to your image, i should use 2 black wires from the extesion and 1 yellow wire, and make a 4 pin molex that way?
Thanks, ill really appreciate some further instructions
You'd need at least 3 separate molex threads on the psu, i dont know if there's one like that.
Try running 3 470/480 on one molex chain and see what happens.
It is not trial error, it's the laws of physics.
3 * 70W => 210W on ONE 18AWG molex 12V wire. That is 17Amps on a 18AWG wire that can handle 10Amps max.
For a few minutes it may work until it warms up enough to start melting the connector housing and burning the dust in the air onto the metal connector. I've seen this at least 50 times from my customers bringing in the burnt cables and PSUs for repair.
I use evga psu, and they say you can use the sata output from the psu to connect molex cables and viceversa, and i started a ticket on their website and they send me 2 string of molex cables for free when i ask about where i could buy more molex cables for my psu