Do I need a second pcie cable for my 3070

[Shreyas1]

Hello,

 

Just got a new 3070, no signal. Wondering if I need to use 2 pcie cables rather than one with 2 pcie ports. Thanks

 

[dreamcast4599]

always best to use two separate pcie power cables for a gpu for optimal power delivery

[Shreyas1]

4 minutes ago, dreamcast4599 said:

always best to use two separate pcie power cables for a gpu for optimal power delivery

Alright thanks. Not doing so can lead to the "no output detected" issue I presume?

[Bombastinator]

It is still likely to at least work sort of though.  I suppose the PSU could detect a “too much wattage through those wires” and shut down that cable.  Another possible is the thing can’t put enough juice through the cable to be able to light up the card at all.  What PSU do you have? Not that I could tell from a model but someone might be able to. 

[Shreyas1]

3 hours ago, Bombastinator said:

It is still likely to at least work sort of though.  I suppose the PSU could detect a “too much wattage through those wires” and shut down that cable.  Another possible is the thing can’t put enough juice through the cable to be able to light up the card at all.  What PSU do you have? Not that I could tell from a model but someone might be able to. 

Seasonic focus plus gold 500w

Edit: 550w

Also wondering where I could pick up spare cables for this PSU, given that I am one short for the pcie cable

[Bombastinator]

1 minute ago, Shreyas1 said:

Seasonic focus plus gold 500w

 

Also wondering where I could pick up spare cables for this PSU, given that I am one short for the pcie cable

Only from seasonic, and they will need your model number.  If they have any.  The problem with detachable PSU cables is they’re part of the PSU.  They’re not standardized.  There might be someone who has reverse engineered the cable and is selling third party.  Got to trust the seller though.  3rd party Replacement cables have a rep for not working or doing bad things.

[Shreyas1]

3 minutes ago, Bombastinator said:

Only from seasonic, and they will need your model number.  If they have any.  The problem with detachable PSU cables is they’re part of the PSU.  They’re not standardized.  There might be someone who has reverse engineered the cable and is selling third party.  Got to trust the seller though.  3rd party Replacement cables have a rep for not working or doing bad things.

damn, i guess i have to ask them then

[dreamcast4599]

17 minutes ago, Shreyas1 said:

damn, i guess i have to ask them then

ouch yeah id look into upgrading your psu 500 watts is not really enough 750 or higher is better also nvidia recommends a 650 watt or better psu for your gpu if the psu cant supply enough watts to the gpu then the gpu wll not power on and or run

[Bombastinator]

28 minutes ago, Shreyas1 said:

damn, i guess i have to ask them then

Best policy.  You might be able to find something that would fit the port but it would also have to be wired right which is hard to guarantee. Also as @dreamcast4599mentioned there very well may not be enough wattage for that card to start with.

Edited July 24, 2021 by Bombastinator

[Shreyas1]

3 minutes ago, Bombastinator said:

Best policy.  You might be able to find something that would fit the port but it would also have to be wired right which is hard to guarantee. Also as @dreamcast4599mentioned there very well may not be enough wattage for that card to start with.

I feel that 550w should at least allow it to start up though, it might shut down during heavy load but even pcpp says its good.

[Bombastinator]

1 minute ago, Shreyas1 said:

I feel that 550w should at least allow it to start up though, it might shut down during heavy load but even pcpp says its good.

Perhaps if you’ve got a real lean running cpu. Still sounds potentially iffy. 

[Shreyas1]

1 minute ago, Bombastinator said:

Perhaps if you’ve got a real lean running cpu. Still sounds potentially iffy. 

r5 2600?

[Bombastinator]

Just now, Shreyas1 said:

r5 2600?

Lean.  It’s a 65w chip. It’s the OCed 8 core stuff that can eat lots power.  With no OC and maybe laying off the usb3 powered stuff you could make it. 

[Forleb]

500W Is simply too low; You're probably tripping OCP. The bare minimum you should go with is 650W, but preferably 750W. Segotep GP units are going for decent prices on Newegg right now, and they're fully modular 80+ Gold certified.

[Bombastinator]

1 minute ago, Forleb said:

500W Is simply too low; You're probably tripping OCP. The bare minimum you should go with is 650W, but preferably 750W. Segotep GP units are going for decent prices on Newegg right now, and they're fully modular 80+ Gold certified.

Is it 500w or 550? 550 would be scraping bottom and without a low power cpu he couldn’t even make it with that.  There’s a decent chance you’re right about the OCP.  OCP will shut everything down and there is sometimes a distinct click from the PSU.  More PSU is the better part of valor.

[Shreyas1]

3 minutes ago, Bombastinator said:

Is it 500w or 550? 550 would be scraping bottom and without a low power cpu he couldn’t even make it with that.  There’s a decent chance you’re right about the OCP.  OCP will shut everything down and there is sometimes a distinct click from the PSU.  More PSU is the better part of valor.

 

7 minutes ago, Forleb said:

500W Is simply too low; You're probably tripping OCP. The bare minimum you should go with is 650W, but preferably 750W. Segotep GP units are going for decent prices on Newegg right now, and they're fully modular 80+ Gold certified.

Wouldnt OCP mean that everything will shut off? That's not what's happening in my case, all the fans and lights still remain on but there's no signal being outputted

[dreamcast4599]

54 minutes ago, Shreyas1 said:

 

Wouldnt OCP mean that everything will shut off? That's not what's happening in my case, all the fans and lights still remain on but there's no signal being outputted

a low wattage psu can cause a gpu to not powert on while still providing minimal power to fans lights etc i run a 1000 watt seasonic psu in my rig

[Shreyas1]

Just now, dreamcast4599 said:

a low wattage psu can cause a gpu to not powert on while still providing minimal power to fans lights etc i run a 1000 watt seasonic psu in my rig

Ah ok. I'll try swapping out the PSU if I get the chance then

[Bombastinator]

9 minutes ago, Shreyas1 said:

Ah ok. I'll try swapping out the PSU if I get the chance then

Might be one of those things where it depends on how much seasonic wants for that second cable.  If it’s like $15 it might be worth it just to have a complete PSU even if it doesn’t work for your 3070.  If they want $60 though that’s more than half what a guaranteed gud’nuf PSU is so screw it.  Just buy another PSU.

[Shreyas1]

20 minutes ago, Bombastinator said:

Might be one of those things where it depends on how much seasonic wants for that second cable.  If it’s like $15 it might be worth it just to have a complete PSU even if it doesn’t work for your 3070.  If they want $60 though that’s more than half what a guaranteed gud’nuf PSU is so screw it.  Just buy another PSU.

yeah of course. Ill try to see if I can get my hands on a different PSU as well (one with more wattage).

[Middcore]

No Focus Plus Gold 500W exists that I can find. The lowest wattage Focus Plus Gold unit is 550W. 

[Shreyas1]

1 hour ago, Middcore said:

No Focus Plus Gold 500W exists that I can find. The lowest wattage Focus Plus Gold unit is 550W. 

Did I type 500? I meant 550. My bad 

[Youn]

6 hours ago, Shreyas1 said:

Hello,

 

Just got a new 3070, no signal. Wondering if I need to use 2 pcie cables rather than one with 2 pcie ports. Thanks

 

 

 

So, the real answer to your question is a pigtail is good for a maximum of 220w of power. All instructions say avoid using above that. The TDP for a 3070 card is 220w. So, you could run it on a single cable if you don't mind the cable running at the pre-melting point of the plastic on the outside of the cable. If for any reason, you end up taxing the card and go above the 100% power usage, then your wires could melt. Is it really worth risking it for the cost of just hooking up a second cable?

 

 

[Shreyas1]

7 minutes ago, Youn said:

 

 

So, the real answer to your question is a pigtail is good for a maximum of 220w of power. All instructions say avoid using above that. The TDP for a 3070 card is 220w. So, you could run it on a single cable if you don't mind the cable running at the pre-melting point of the plastic on the outside of the cable. If for any reason, you end up taxing the card and go above the 100% power usage, then your wires could melt. Is it really worth risking it for the cost of just hooking up a second cable?

 

 

Makes sense. Still, would it fail to output signal at all? At any rate, I plan to test with a 650w PSU with 2 cables tomorrow anyways, so I'll see what happens then.

[Bombastinator]

3 minutes ago, Shreyas1 said:

Makes sense. Still, would it fail to output signal at all? At any rate, I plan to test with a 650w PSU with 2 cables tomorrow anyways, so I'll see what happens then.

Depends on how the internal structure of the PSU is set up.  Which is black box to some degree. PSU makers do weird things with rails and logic and such.  It might be set up so it simply can’t pull enough power through one connector.  Which would make sense since it appears to be an on the verge of melting thing.  So it doesn’t necessarily mean WILL work work with a new PSU, as there could be something completely different wrong (for which only an RMA will likely do) but it eliminates one possibility.