KingEngineRevUp
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 17:15:35
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aardvark1134
rain2_usa
I see all of these arguments about not using both connectors in a daisy chain invalid. There's no reason to have a daisy chain connector capable of having 2 - 8pin connectors if it wasn't meant to be used at the same time. If there was an issue, there would be a warning label NOT to use it under certain circumstances; not buried on a website somewhere. There would/should be a cap/sticker on one of the connectors or similar stating as such.
And also remember the days of the 4pin molex. I know I daisy chained the heck out of those in the 486/Pentium days. CD, 5-1/4" floppy, 3-1/2" floppy, tape drive, zip drive, Master and Slave hard drives, Fans, etc. As long as you had the proper wattage PSU, it was all good.
My 2 cents.
Have you ever seen any power strips in your entire life? Trying taking that 8 outlet 15 amp power strip and plugging a sweeper or hair dryer into every single one of them at the same time...
Sorry but that's a poor example, or rather a good example of people not understanding the issue (or non-issue) here. An outlet maxes out at 13A and a blow dryey nearly exceeds that by itself. That's not the case here. That's like saying you're plugging in one device that would draw out the whole rated power deliver of a PSU and obviously we're not...
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aardvark1134
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 17:16:06
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Hey look an official Corsair post saying they reccomend 1 cable per power connector on the card... https://ibb.co/64j3k83
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jankerson
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 17:29:39
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ilkali
Intoxicus
The connectors are Molex Mini Fit Jr 5556. They are rated at 13a @ 12v giving us 156W (not 150W, lol.)
Even if a cable can support more than 156W the connector will bottleneck that.
I believe you're wrong here. This specification is 13A per circuit, not whole connector. 13A is the max limit, 11A is more realistic as I think it is the HCS standars, which gives 12*3*11 = 396 W of power per connector safely.
This number is the molex specification and it should be obeyed as going over that is dangerous. 150W limit of the PCIe specification is a more arbitrary number to ensure a wide array of compatibility. Anyway, with the FE cards, nvidia is bypassing the PCIe specification but they still have to abide by molex standards.
Also main reason that the 3080 and 3090's shouldnt be daisy chained is not their sustained power consumption but their power spikes. It's been shown that 3080s can have momentary power spikes of 489 Watts while 3090's can reach as high as 573 Watt, which is well above the molex specifications and is dangerous to daisy chain. But for a 3060 TI, which is just pulling 200 watts normally while reaching 340-350 momentary peaks, it's not the end of the world to use a daisy chained cable as you're still within the specs.
That's actually 976W for the 20ms power spikes.
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KingEngineRevUp
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 17:32:33
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aardvark1134
Hey look an official Corsair post saying they reccomend 1 cable per power connector on the card...
https://ibb.co/64j3k83
Yes... But that's NOT the discussion here. It's a 3x 8-pin and having a dedicated and daisy chain. What you're referring to is when the 2080 Tis started drawing 250W-300W with 2x 8-pins.
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jankerson
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 17:39:32
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KingEngineRevUp
aardvark1134
Hey look an official Corsair post saying they reccomend 1 cable per power connector on the card...
https://ibb.co/64j3k83
Yes... But that's NOT the discussion here. It's a 3x 8-pin and having a dedicated and daisy chain. What you're referring to is when the 2080 Tis started drawing 250W-300W with 2x 8-pins.
That's 375W from 2x 8 Pins for a 2080Ti FTW3 Ultra.
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KingEngineRevUp
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 17:48:35
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jankerson
KingEngineRevUp
aardvark1134
Hey look an official Corsair post saying they reccomend 1 cable per power connector on the card...
https://ibb.co/64j3k83
Yes... But that's NOT the discussion here. It's a 3x 8-pin and having a dedicated and daisy chain. What you're referring to is when the 2080 Tis started drawing 250W-300W with 2x 8-pins.
That's 375W from 2x 8 Pins for a 2080Ti FTW3 Ultra.
Thank you for adding that, I was talking about the FE off my memory. My bad. But yes, a 375W card does warrant dedicated cables. To others: Now lets move onto these "power spike" conversations. If you guys believe 150W is the limit, why would they recommend 2x 8-pin and PCI-E to deliver 370W to a 3080 FE if it's reaching its limit? That's because there's factors of safety! Lets take a look at the 3090 FE, it draws 400W max! That means each PCI-E has to draw more than 150W, that's 162.5W each! *gasp* Now all the 3090 FE should be exploding right? No... because again... We did the math in my post up there... a good PCI-E cable is speced (pin, wire, connectors) to take 288W loads...
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kelkel1
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 17:50:08
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The terminals, Molex 5556 series, used in six and eight pin PCI-E, i.e. 'GPU' cables, depending on whether brass or phosphor bronze, are rated for 8A (Brass)/7A (Phosphor Bronze) and 7A (Brass)/6A (Phosphor Bronze) respectively, using 18AWG wire. Given a two foot cable (four foot round-trip), the ampacity of 18AWG CU, depending on temperature and number of conductors in the cable, may be as high as 15A, but typically >8A. 6A @ 12V = 72W per conductor, three +12V conductors per cable = 216W. Two eight pin PCI-E cables theoretically carry 432W.
post edited by kelkel1 - 2020/12/04 17:52:45
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jankerson
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 17:51:58
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KingEngineRevUp
jankerson
KingEngineRevUp
aardvark1134
Hey look an official Corsair post saying they reccomend 1 cable per power connector on the card...
https://ibb.co/64j3k83
Yes... But that's NOT the discussion here. It's a 3x 8-pin and having a dedicated and daisy chain. What you're referring to is when the 2080 Tis started drawing 250W-300W with 2x 8-pins.
That's 375W from 2x 8 Pins for a 2080Ti FTW3 Ultra.
Thank you for adding that, I was talking about the FE off my memory. My bad. But yes, a 375W card does warrant dedicated cables.
To others:
Now lets move onto these "power spike" conversations. If you guys believe 150W is the limit, why would they recommend 2x 8-pin and PCI-E to deliver 370W to a 3080 FE if it's reaching its limit? That's because there's factors of safety!
Lets take a look at the 3090 FE, it draws 400W max! That means each PCI-E has to draw more than 150W, that's 162.5W each! *gasp* Now all the 3090 FE should be exploding right? No... because again... We did the math in my post up there... a good PCI-E cable is speced (pin, wire, connectors) to take 288W loads...
The actual real power spikes are 976 Watts for about 20ms.
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KingEngineRevUp
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 18:09:59
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jankerson
KingEngineRevUp
jankerson
KingEngineRevUp
aardvark1134
Hey look an official Corsair post saying they reccomend 1 cable per power connector on the card...
https://ibb.co/64j3k83
Yes... But that's NOT the discussion here. It's a 3x 8-pin and having a dedicated and daisy chain. What you're referring to is when the 2080 Tis started drawing 250W-300W with 2x 8-pins.
That's 375W from 2x 8 Pins for a 2080Ti FTW3 Ultra.
Thank you for adding that, I was talking about the FE off my memory. My bad. But yes, a 375W card does warrant dedicated cables.
To others:
Now lets move onto these "power spike" conversations. If you guys believe 150W is the limit, why would they recommend 2x 8-pin and PCI-E to deliver 370W to a 3080 FE if it's reaching its limit? That's because there's factors of safety!
Lets take a look at the 3090 FE, it draws 400W max! That means each PCI-E has to draw more than 150W, that's 162.5W each! *gasp* Now all the 3090 FE should be exploding right? No... because again... We did the math in my post up there... a good PCI-E cable is speced (pin, wire, connectors) to take 288W loads...
The actual real power spikes are 976 Watts for about 20ms.
You know when a civil engineer designs a bridge they'll give it a load rating? And it usually has a factor of safety of 10. That's bec they account for impulses and dynamic effects. Same thing with electronics. You rate a cable for it's normal use but you, as a Engineer, account for numbers they wouldn't see or understand. Now what are those FOS, I'd like to hear it from a EE. But the fact seasonic made that illustration that a dedicated and daisy chain is okay makes me blei they factor those spikes in. Otherwise, why would they risk their reputation? Specially when most if not all their high end PSU come with more than just 2 PCI-E cables. They don't benefit in tricking us like the OP thinks. OP thinks seasonic has an evil agenda to destroy GPU apparently.
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jankerson
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 18:21:52
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KingEngineRevUp
jankerson
KingEngineRevUp
jankerson
KingEngineRevUp
aardvark1134
Hey look an official Corsair post saying they reccomend 1 cable per power connector on the card...
https://ibb.co/64j3k83
Yes... But that's NOT the discussion here. It's a 3x 8-pin and having a dedicated and daisy chain. What you're referring to is when the 2080 Tis started drawing 250W-300W with 2x 8-pins.
That's 375W from 2x 8 Pins for a 2080Ti FTW3 Ultra.
Thank you for adding that, I was talking about the FE off my memory. My bad. But yes, a 375W card does warrant dedicated cables.
To others:
Now lets move onto these "power spike" conversations. If you guys believe 150W is the limit, why would they recommend 2x 8-pin and PCI-E to deliver 370W to a 3080 FE if it's reaching its limit? That's because there's factors of safety!
Lets take a look at the 3090 FE, it draws 400W max! That means each PCI-E has to draw more than 150W, that's 162.5W each! *gasp* Now all the 3090 FE should be exploding right? No... because again... We did the math in my post up there... a good PCI-E cable is speced (pin, wire, connectors) to take 288W loads...
The actual real power spikes are 976 Watts for about 20ms.
You know when a civil engineer designs a bridge they'll give it a load rating? And it usually has a factor of safety of 10. That's bec they account for impulses and dynamic effects.
Same thing with electronics. You rate a cable for it's normal use but you, as a Engineer, account for numbers they wouldn't see or understand.
Now what are those FOS, I'd like to hear it from a EE.
But the fact seasonic made that illustration that a dedicated and daisy chain is okay makes me blei they factor those spikes in. Otherwise, why would they risk their reputation? Specially when most if not all their high end PSU come with more than just 2 PCI-E cables. They don't benefit in tricking us like the OP thinks.
OP thinks seasonic has an evil agenda to destroy GPU apparently.
The numbers come straight from Corsair and NVIDIA. Corsair actually tested it, it's 976 Watts transient power spikes for 20ms.
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KingEngineRevUp
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 18:27:00
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@jankerson I'm actually not sure if you understand what I'm trying to say, let me clarify a few things, probably my fault after reading my post again.
When I said power spikes, I meant to say Power spoke guys, because these are the people that believe a PCI-E cables limit is 150W when it's not, and the FE 3090 proves it already.
Now the power spikes, I'm not disputing that number, I'm saying that they're going to be accounted for when a power cable is designed.
No one designs a cable and tells you it's 100% max drawing capability before failure. The whole point is to try to mitigate failure, so they're going to usually tell you a fraction of the cables true limit before it combus into flames.
Hope that clarifies my previous post.sorry.
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jankerson
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 18:33:42
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KingEngineRevUp
@jankerson I'm actually not sure if you understand what I'm trying to say, let me clarify a few things, probably my fault after reading my post again.
When I said power spikes, I meant to say Power spoke guys, because these are the people that believe a PCI-E cables limit is 150W when it's not, and the FE 3090 proves it already.
Now the power spikes, I'm not disputing that number, I'm saying that they're going to be accounted for when a power cable is designed.
No one designs a cable and tells you it's 100% max drawing capability before failure. The whole point is to try to mitigate failure, so they're going to usually tell you a fraction of the cables true limit before it combus into flames.
Hope that clarifies my previous post.sorry.
It's not the wire that's the issue, the connectors or should I say the pins in the connectors that are the issue. The pins heat up and melt the connectors. The real issue with PSUs in general is there isn't any enforceable industry standard. So going outside of PCIe standard can be risky.
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Intoxicus
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 19:18:30
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ilkali
Intoxicus
The connectors are Molex Mini Fit Jr 5556. They are rated at 13a @ 12v giving us 156W (not 150W, lol.)
Even if a cable can support more than 156W the connector will bottleneck that.
I believe you're wrong here. This specification is 13A per circuit, not whole connector. 13A is the max limit, 11A is more realistic as I think it is the HCS standars, which gives 12*3*11 = 396 W of power per connector safely.
This number is the molex specification and it should be obeyed as going over that is dangerous. 150W limit of the PCIe specification is a more arbitrary number to ensure a wide array of compatibility. Anyway, with the FE cards, nvidia is bypassing the PCIe specification but they still have to abide by molex standards.
Also main reason that the 3080 and 3090's shouldnt be daisy chained is not their sustained power consumption but their power spikes. It's been shown that 3080s can have momentary power spikes of 489 Watts while 3090's can reach as high as 573 Watt, which is well above the molex specifications and is dangerous to daisy chain. But for a 3060 TI, which is just pulling 200 watts normally while reaching 340-350 momentary peaks, it's not the end of the world to use a daisy chained cable as you're still within the specs.
The mini fit jr specs are for the pin itself, not the whole connector. I can tell you have not even looked at the spec sheet for the mini fit jr 5556
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Intoxicus
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 19:27:46
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KingEngineRevUp
Yes... But that's NOT the discussion here. It's a 3x 8-pin and having a dedicated and daisy chain. What you're referring to is when the 2080 Tis started drawing 250W-300W with 2x 8-pins.
Oh really now. You bring that up now but ignore it's a factor in the Debauer video you linked... Btw this is not a bridge, that was a massive false equivalence you made there. kelkel1
The terminals, Molex 5556 series, used in six and eight pin PCI-E, i.e. 'GPU' cables, depending on whether brass or phosphor bronze, are rated for 8A (Brass)/7A (Phosphor Bronze) and 7A (Brass)/6A (Phosphor Bronze) respectively, using 18AWG wire.
Given a two foot cable (four foot round-trip), the ampacity of 18AWG CU, depending on temperature and number of conductors in the cable, may be as high as 15A, but typically >8A.
6A @ 12V = 72W per conductor, three +12V conductors per cable = 216W.
Two eight pin PCI-E cables theoretically carry 432W.
Good catch, it seems I got mixed up and used current rating from the wrong spec sheet in my math. Been looking at too many similar looking molex mini spec sheets, lol. jankerson
jankerson
It's not the wire that's the issue, the connectors or should I say the pins in the connectors that are the issue. The pins heat up and melt the connectors.
The real issue with PSUs in general is there isn't any enforceable industry standard.
So going outside of PCIe standard can be risky.
You nailed it and thank you. In a sense it kinda doesn't matter what the cable can handle as long as it's at least as much as the connectors will handle. Intel does release ATX PSU specs. But they are NOT mandatory per sey. They're *recommended* specs. The reason I'm so apprehensive about using both connectors on a daisy chain has a lot to do with the variability in adherence to the ATX specs released by Intel. If the ATX specs were followed properly this would not really be much of an issue as it seems to be.
post edited by Intoxicus - 2020/12/04 19:29:59
"Humans are not rational animals, humans are rationalizing animals." -Robert A Heinlein
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jankerson
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 20:00:56
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Intoxicus
KingEngineRevUp
Yes... But that's NOT the discussion here. It's a 3x 8-pin and having a dedicated and daisy chain. What you're referring to is when the 2080 Tis started drawing 250W-300W with 2x 8-pins.
Oh really now.
You bring that up now but ignore it's a factor in the Debauer video you linked...
Btw this is not a bridge, that was a massive false equivalence you made there.
kelkel1
The terminals, Molex 5556 series, used in six and eight pin PCI-E, i.e. 'GPU' cables, depending on whether brass or phosphor bronze, are rated for 8A (Brass)/7A (Phosphor Bronze) and 7A (Brass)/6A (Phosphor Bronze) respectively, using 18AWG wire.
Given a two foot cable (four foot round-trip), the ampacity of 18AWG CU, depending on temperature and number of conductors in the cable, may be as high as 15A, but typically >8A.
6A @ 12V = 72W per conductor, three +12V conductors per cable = 216W.
Two eight pin PCI-E cables theoretically carry 432W.
Good catch, it seems I got mixed up and used current rating from the wrong spec sheet in my math. Been looking at too many similar looking molex mini spec sheets, lol.jankerson
jankerson
It's not the wire that's the issue, the connectors or should I say the pins in the connectors that are the issue. The pins heat up and melt the connectors.
The real issue with PSUs in general is there isn't any enforceable industry standard.
So going outside of PCIe standard can be risky.
You nailed it and thank you. In a sense it kinda doesn't matter what the cable can handle as long as it's at least as much as the connectors will handle.
Intel does release ATX PSU specs. But they are NOT mandatory per sey. They're *recommended* specs.
The reason I'm so apprehensive about using both connectors on a daisy chain has a lot to do with the variability in adherence to the ATX specs released by Intel.
If the ATX specs were followed properly this would not really be much of an issue as it seems to be.
There will always be those who go outside of the recommendations. People will even post etc. that they did, but what you won't ever see is those people post back that they burned something up by being stupid. Sometimes things seem to work, until they don't.  There is a lot of dangerous information out there, even videos by supposed self proclaimed experts that's don't have the proper equipment and knowledge to do the testing that is needed. Just because someone has a YT channel doesn't mean they know what they are talking about. AND ALMOST NONE OF THEM DO, like almost all except a few, VERY FEW when it comes to PSUs you could narrow that down to one, maybe two. One actually that has the knowledge (He is a PHD in the field), proper equipment and experience to actually test PSUs. That's Aris that runs Cybernetics and his YT channel is Hardware Busters. Other than that, NOPE.
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KingEngineRevUp
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 20:19:46
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It's not the wire that's the issue, the connectors or should I say the pins in the connectors that are the issue. The pins heat up and melt the connectors.
The real issue with PSUs in general is there isn't any enforceable industry standard.
So going outside of PCIe standard can be risky.
Technically, putting 2x 8-pin on a GPU is out of PCI-E standard last I checked, so what risk are we taking? They haven't put their stamp or approved 2X 8-pin let alone 3X 8-pin. Unless if there's more research done, I see no failure mode that has been pin pointed the cause of failure. For example, poor connection can cause the load to move to the other lines. "Some cards use two 8-pin connectors, but this has not been standardized yet as of 2018, therefore such cards must not carry the official PCI Express logo." I do not have access to PCI Express® Base Specification Revision 5.0 Version, are you aware of any changes I may not be? You bring that up now but ignore it's a factor in the Debauer video you linked... I don't even know what you're talking about. You want to clarify? Lets revisit one of your post also. The connectors are Molex Mini Fit Jr 5556. They are rated at 13a @ 12v giving us 156W (not 150W, lol.)
Even if a cable can support more than 156W the connector will bottleneck that. Where are you getting this number because that's not what I see on the spec sheet. Also, the 3090 FE draws 400W and that puts a load of 162.5W per a PCI-E cable. That alone is proof your 156W number doesn't make much sense.
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KingEngineRevUp
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 20:23:40
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One actually that has the knowledge (He is a PHD in the field), proper equipment and experience to actually test PSUs. That's Aris that runs Cybernetics and his YT channel is Hardware Busters.
Other than that, NOPE.
You mean Seasonic? A company that makes PSUs and even PSU for other PSU companies?  Has any other company or professional come out and disputed against seasonics illustration that you are aware of? How about EVGA? Do they count?  What about ASUS, do they count?  
post edited by KingEngineRevUp - 2020/12/04 20:33:42
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jankerson
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 20:36:54
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KingEngineRevUp
One actually that has the knowledge (He is a PHD in the field), proper equipment and experience to actually test PSUs. That's Aris that runs Cybernetics and his YT channel is Hardware Busters.
Other than that, NOPE.
You mean Seasonic? A company that makes PSUs and even PSU for other PSU companies?
Has any other company or professional come out and disputed against seasonics illustration that you are aware of?
I would hope not..... (Corsair has said it's best to use 3 separate cables, as has EVGA for that matter) Plenty of self proclaimed experts have however, using one daisy chained cable on high powered GPUs.
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KingEngineRevUp
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 20:38:51
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jankerson
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 20:47:09
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I will just leave this right here: EVGA_JacobF
Nice rig. On the FTW3 running one cable off a splitter is fine (2 separate) and having 3 separate cables won't really make a difference, however, as many separate cables as possible is TECHNICALLY more ideal. Personally I would run 3 separate if your PSU supported it.
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KingEngineRevUp
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 20:53:42
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jankerson
I will just leave this right here:
EVGA_JacobF
Nice rig. On the FTW3 running one cable off a splitter is fine (2 separate) and having 3 separate cables won't really make a difference, however, as many separate cables as possible is TECHNICALLY more ideal. Personally I would run 3 separate if your PSU supported it.
No offense, but it's like you selectively read it like this. "Nice rig. On the FTW3 running [...] as many separate cables as possible [...] I would run 3 separate if your PSU supported it." This thread is dead. Seasonic, EVGA, ASUS have all come out and said dedicated and daisy chain is fine. If you want to have a peace of mind, go ahead and do 3 dedicated, it's not going to hurt you. But don't fear monger people into thinking something is "against some standard" when you guys haven't presented anything. It's fear mongering. My issue with OP, he's stating a baseless fact and you're starting to become a part of it.
post edited by KingEngineRevUp - 2020/12/04 20:57:33
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jankerson
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 21:07:23
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KingEngineRevUp
jankerson
I will just leave this right here:
EVGA_JacobF
Nice rig. On the FTW3 running one cable off a splitter is fine (2 separate) and having 3 separate cables won't really make a difference, however, as many separate cables as possible is TECHNICALLY more ideal. Personally I would run 3 separate if your PSU supported it.
No offense, but it's like you selectively read it like this.
"Nice rig. On the FTW3 running [...] as many separate cables as possible [...] I would run 3 separate if your PSU supported it."
This thread is dead. Seasonic, EVGA, ASUS have all come out and said dedicated and daisy chain is fine. If you want to have a peace of mind, go ahead and do 3 dedicated, it's not going to hurt you. But don't fear monger people into thinking something is "against some standard" when you guys haven't presented anything. It's fear mongering.
My issue with OP, he's stating a baseless fact and you're starting to become a part of it.
Were did I say that one couldn't hook up the 3x 8 pin card using 2 cables one being daisy chained? As long as the PSU is of enough wattage and quality it should be fine. However if the PSU has enough cables to run 3 separate then it is best to do so, and zero reason not to. 750W PSUs and under don't normally have enough cables to run 3, 750W is on the light side for a 3080 and 3090 so there is always that. 850W and greater do, well the high quality ones do anyway.
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Intoxicus
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 21:14:37
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jankerson
I will just leave this right here:
EVGA_JacobF
Nice rig. On the FTW3 running one cable off a splitter is fine (2 separate) and having 3 separate cables won't really make a difference, however, as many separate cables as possible is TECHNICALLY more ideal. Personally I would run 3 separate if your PSU supported it.
EVGA Jacob's personal rig is running a splitter according to the pic in his twitter... https://twitter.com/FlangerOfTowels/status/1334615813127487493
jankerson
There will always be those who go outside of the recommendations.
People will even post etc. that they did, but what you won't ever see is those people post back that they burned something up by being stupid.
Sometimes things seem to work, until they don't.
There is a lot of dangerous information out there, even videos by supposed self proclaimed experts that's don't have the proper equipment and knowledge to do the testing that is needed.
Just because someone has a YT channel doesn't mean they know what they are talking about.
AND ALMOST NONE OF THEM DO, like almost all except a few, VERY FEW when it comes to PSUs you could narrow that down to one, maybe two.
One actually that has the knowledge (He is a PHD in the field), proper equipment and experience to actually test PSUs. That's Aris that runs Cybernetics and his YT channel is Hardware Busters.
Other than that, NOPE.
It's interesting how almost no one that has disagreed with me has referenced specs or brought actual proof. So far one person corrected me on an error I made by referencing the Molex Mini Fit Jr 5556 specs. I'm really hoping this gains enough traction that some people that have the resources, etc to test this properly get into it. I'll ask this: How can one cable with two connections do the job of two cables? If that works then why do we need 3x8 pin connections and not 2 x 8pin? At a fundamental level something does not add up about the daisy chains cables for the 2000 series and 3000 series. Also even though anecdotal if one daisy chain can supply the same power as 2 X 8 pin cables then why was my 2070 having stability issues until I went to two separate cables. That's using the same *EVGA* Supernova G3 Gold 1000W I have now. Does that mean EVGA PSUs are not as high quality as they're reputed to be? Which if that is the case adds to the idea that if PSU are that variable on following spec it's not worth the risk. I think we can also ignore KingEngineRevUpNew at this point. Unless he brings in actual facts and data and starts referencing specs I don't see the value in engaging with him any further. He seems committed to me being wrong. And I'm fine with being wrong, being wrong means I eventually do get to the right answer. Need to bring actual data with references to the table and not engage in logical fallacies to do it though...
"Humans are not rational animals, humans are rationalizing animals." -Robert A Heinlein
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jankerson
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 21:18:10
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Intoxicus
jankerson
I will just leave this right here:
EVGA_JacobF
Nice rig. On the FTW3 running one cable off a splitter is fine (2 separate) and having 3 separate cables won't really make a difference, however, as many separate cables as possible is TECHNICALLY more ideal. Personally I would run 3 separate if your PSU supported it.
EVGA Jacob's personal rig is running a splitter according to the pic in his twitter...
https://twitter.com/FlangerOfTowels/status/1334615813127487493
jankerson
There will always be those who go outside of the recommendations.
People will even post etc. that they did, but what you won't ever see is those people post back that they burned something up by being stupid.
Sometimes things seem to work, until they don't.
There is a lot of dangerous information out there, even videos by supposed self proclaimed experts that's don't have the proper equipment and knowledge to do the testing that is needed.
Just because someone has a YT channel doesn't mean they know what they are talking about.
AND ALMOST NONE OF THEM DO, like almost all except a few, VERY FEW when it comes to PSUs you could narrow that down to one, maybe two.
One actually that has the knowledge (He is a PHD in the field), proper equipment and experience to actually test PSUs. That's Aris that runs Cybernetics and his YT channel is Hardware Busters.
Other than that, NOPE.
It's interesting how almost no one that has disagreed with me has referenced specs or brought actual proof. So far one person corrected me on an error I made by referencing the Molex Mini Fit Jr 5556 specs.
I'm really hoping this gains enough traction that some people that have the resources, etc to test this properly get into it.
I'll ask this:
How can one cable with two connections do the job of two cables? If that works then why do we need 3x8 pin connections and not 2 x 8pin?
At a fundamental level something does not add up about the daisy chains cables for the 2000 series and 3000 series.
Also even though anecdotal if one daisy chain can supply the same power as 2 X 8 pin cables then why was my 2070 having stability issues until I went to two separate cables. That's using the same *EVGA* Supernova G3 Gold 1000W I have now. Does that mean EVGA PSUs are not as high quality as they're reputed to be?
Which if that is the case adds to the idea that if PSU are that variable on following spec it's not worth the risk.
I think we can also ignore KingEngineRevUpNew at this point. Unless he brings in actual facts and data and starts referencing specs I don't see the value in engaging with him any further. He seems committed to me being wrong. And I'm fine with being wrong, being wrong means I eventually do get to the right answer. Need to bring actual data with references to the table and not engage in logical fallacies to do it though...
MOORES LAW.. Yes, it really is that simple and THAT trumps anything and everything. Because that is not an opinion, that is hard based fact.
post edited by jankerson - 2020/12/04 21:20:41
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KingEngineRevUp
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 21:38:11
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jankerson
Were did I say that one couldn't hook up the 3x 8 pin card using 2 cables one being daisy chained?
As long as the PSU is of enough wattage and quality it should be fine.
However if the PSU has enough cables to run 3 separate then it is best to do so, and zero reason not to.
750W PSUs and under don't normally have enough cables to run 3, 750W is on the light side for a 3080 and 3090 so there is always that.
850W and greater do, well the high quality ones do anyway.
If that is your stance, then I'm in agreement with it. Intoxicus
I think we can also ignore KingEngineRevUpNew at this point. Unless he brings in actual facts and data and starts referencing specs I don't see the value in engaging with him any further. He seems committed to me being wrong. And I'm fine with being wrong, being wrong means I eventually do get to the right answer. Need to bring actual data with references to the table and not engage in logical fallacies to do it though...
Because there is no standard or spec for this setup. PCI-SIG doesn't even recognize what manufacturers have been doing with 2x 8-pin. Some cards use two 8-pin connectors, but this has not been standardized yet as of 2018, therefore such cards must not carry the official PCI Express logo.
https://en.wikipedia.org/wiki/PCI_Express
You can ignore me, but address Seasonic, EVGA and ASUS. Then you would have proven your point. To anyone else that has to read through this thread, Intoxicus has no basis to his claims. Other companies have come out and said using a dedicated and splitter is acceptable.
post edited by KingEngineRevUp - 2020/12/04 21:45:37
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jankerson
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 22:15:48
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Actually acceptable is a relative term.
There is still MOORES LAW that does trump anything and everything else.
There isn't any 100% cover all situations answer to using a daisy chained cable.
Those same companies that say it's acceptable also say it's better to use 3 separate cables.
And it really is.
That Seasonic picture came out long before the really powerful cards came out, yeah it's been around for awhile now.
We didn't have 500W GPUs back then like we do now.
i9 9900K @ 5.0 GHz, NH D15, 32 GB GSKILL Trident Z RGB, AORUS Z390 MASTER, EVGA RTX 3080 FTW3 Ultra, Samsung 970 EVO Plus 500GB, Samsung 860 EVO 1TB, Samsung 860 EVO 500GB, ASUS ROG Swift PG279Q, Steel Series APEX PRO, Logitech Gaming Pro Mouse, CM Master Case 5, Corsair AXI 1600W. i7 8086K, AORUS Z370 Gaming 5, 16GB GSKILL RJV 3200, EVGA 2080TI FTW3 Ultra, Samsung 970 EVO 250GB, (2)SAMSUNG 860 EVO 500 GB, Acer Predator XB1 XB271HU, Corsair HXI 850W. i7 8700K, AORUS Z370 Ultra Gaming, 16GB 16GB DDR4 3000, EVGA 1080Ti FTW3 Ultra, Samsung 960 EVO 250GB, Corsair HX 850W.
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Intoxicus
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 22:52:29
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Hence why the default rule of thumb, especially for new builders, should be one cable per GPU power connection.
There's no proven technical benefit to using a daisy chain cable. If anything there are too many possible detriments to using one.
"Humans are not rational animals, humans are rationalizing animals." -Robert A Heinlein
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dmisiur
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 23:10:04
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Those split cables are for low power GPU. I always preferred 1 to 1 myself.
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jankerson
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 23:11:12
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Intoxicus
Hence why the default rule of thumb, especially for new builders, should be one cable per GPU power connection.
There's no proven technical benefit to using a daisy chain cable. If anything there are too many possible detriments to using one.
There aren't any technical benefits of using of using a daisy chained cable period. EVERYTHING would, or should tell people NOT to use them unless they have no other choice.
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KingEngineRevUp
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Re: GPU Power: One cable, One connection; no splitter cables.
2020/12/04 23:44:03
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jankerson
Actually acceptable is a relative term.
There is still MOORES LAW that does trump anything and everything else.
There isn't any 100% cover all situations answer to using a daisy chained cable.
Those same companies that say it's acceptable also say it's better to use 3 separate cables.
And it really is.
That Seasonic picture came out long before the really powerful cards came out, yeah it's been around for awhile now.
We didn't have 500W GPUs back then like we do now.
Of course they'll say it's better to use 3 separate cables, it increases your FOS. That never hurts any design unless if it's a airplane (believe it or not, FOS also generally increases weight in most cases). I think we can all agree on that. But OP made it sound like using a dedicated and daisy chain is as bad as using a daisy chain only on a 2x 8-pin which is an absolute no for the 3080s.
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