GPU - 1 or 2 PCIe Cables?

[Hi P]

GPU: Asus Dual GeForce RTX 2080 Ti OC

PSU: Corsair RM850i

 

My PCIe cable is setup like this (single cable)

- 1x 8-pin - Power Supply

- 2x 8-pin - Graphics Card

 

I just got told on the NVidia GeForce forums that I should do dual cable:

- 2x 8-pin - Power Supply

- 2x 8-pin - Graphics Card  (with the other end of both cables just being left unused)

 

I'm not overclocking the GPU, but it's likely to be stressed during GPU rendering.

 

Should I do the dual cable setup or am I okay on a single one?

Mainly asking because while I do have enough cables to do the dual thing, I'd honestly rather not fit in more cables into the case if I can avoid doing so.

 

Thank you

 

[GrockleTD]

1 minute ago, Hi P said:

GPU: Asus Dual GeForce RTX 2080 Ti OC

PSU: Corsair RM850i

 

My PCIe cable is setup like this (single cable)

- 1x 8-pin - Power Supply

- 2x 8-pin - Graphics Card

 

I just got told on the NVidia GeForce forums that I should do dual cable:

- 2x 8-pin - Power Supply

- 2x 8-pin - Graphics Card  (with the other end of both cables just being left unused)

 

I'm not overclocking the GPU, but it's likely to be stressed during GPU rendering.

 

Should I do the dual cable setup or am I okay on a single one?

Mainly asking because while I do have enough cables to do the dual thing, I'd honestly rather not fit in more cables into the case if I can avoid doing so.

 

Thank you

 

So wait, do you have 2 8 pin PCIe or not?

[Mira Yurizaki]

I believe most graphics cards will refuse to allow the computer to boot unless it has all of the PCIe plugs populated.

 

Also having one PCIe power cable is an indication the PSU was not designed to handle graphics cards of that power.

[COUPER MILLAR]

Jayztwocents did a video on this a few years back. If you are not looking to hit record breaking overclocks just run the one cable with the two 8 pin connectors. Stability wise Jay saw that using two separate 8 pin cables sometimes allowed for slightly higher stable overclocks but not anything that would be noticed in daily operation. 

[Void Master]

I believe he means something like a splitter that is wired to the connector.

Anyway i believe 2  separate connectors is more stable.  

 

[LukeSavenije]

1 minute ago, COUPER MILLAR said:

Jayztwocents did a video on this a few years back. If you are not looking to hit record breaking overclocks just run the one cable with the two 8 pin connectors. Stability wise Jay saw that using two separate 8 pin cables sometimes allowed for slightly higher stable overclocks but not anything that would be noticed in daily operation. 

partly disagree, my single 8 pin 1070 ti is power limited because of it. but to get on this specific card. I would still run with 2, it might be refusing to start up without it

[Hi P]

3 minutes ago, Grockle88 said:

So wait, do you have 2 8 pin PCIe or not?

Sorry I may not understand what you mean (I'm super dumb)

 

A single PCIe cable has one end being 1x 8-Pin and the other end being two 1x 8-pin (daisy chained I believe it's the name?), so I have the single end into my PSU, and the daisy chain end on my GPU

 

3 minutes ago, M.Yurizaki said:

I believe most graphics cards will refuse to allow the computer to boot unless it has all of the PCIe plugs populated.

 

Also having one PCIe power cable is an indication the PSU was not designed to handle graphics cards of that power.

The PSU came with like 3 PCIe cables, so am I okay with a single one?

[Guest]

I think some are confused here. OP means using to dedicated cables rather than the 1 8-pin cable that breaks out into 2x 8-pin.

Should be fine in your use case.

[LukeSavenije]

1 minute ago, Hi P said:

Sorry I may not understand what you mean (I'm super dumb)

 

A single PCIe cable has one end being 1x 8-Pin and the other end being two 1x 8-pin (daisy chained I believe it's the name?), so I have the single end into my PSU, and the daisy chain end on my GPU

that's because one is meant for the cpu power, and the other one for the gpu. just use the double 8 pin cable

[Jurrunio]

Single cable setup will do. Each 8pin PCIe connector is specced to do 150w (so 300w for a single cable with 2 connectors), while the cable itself (with decent 18AWG wires) can carry 360W without going out of spec and need extra cooling. That's why PSU makers use daisy-chained 8pin PCIe connector: it's safe to do that.

 

In the case of the 2080ti, power limit is set to 325w max and 75w of that (maximum) can come from the PCIe slot. Also Nvidia's power balancing circuitry is designed to keep power draw from both PCIe plugs below 150w each, so just a single cable will do.

 

The only exception of consumer cards (so excluding LN2 cards) that using different cables for each power connector is an absolute must as far as I can tell is the R9 295X2, with only 2 PCIe 8pin connector but pushing 500W easily.

[Void Master]

3 minutes ago, Hi P said:

Sorry I may not understand what you mean (I'm super dumb)

 

A single PCIe cable has one end being 1x 8-Pin and the other end being two 1x 8-pin (daisy chained I believe it's the name?), so I have the single end into my PSU, and the daisy chain end on my GPU

 

The PSU came with like 3 PCIe cables, so am I okay with a single one?

It's okay .

but its more stable and better to use 2 cables

[Dissitesuxba11s]

To drill in what others have said with an industry source:

 

Source: https://seasonic.com/faq/# See "Installation Remarks for High Power Consumption Graphics Cards" section.

[Hi P]

1 minute ago, Dissitesuxba11s said:

To drill in what others have said with an industry source:

Yea I have the Standard setup, and I have enough cables for the image just left from it (the third one from left to right)

 

But my question is, why is the dual cable recommended besides the single one? (standard)

 

Does it make a difference in my case?

 

5 minutes ago, Jurrunio said:

In the case of the 2080ti, power limit is set to 325w max and 75w of that (maximum) can come from the PCIe slot. Also Nvidia's power balancing circuitry is designed to keep power draw from both PCIe plugs below 150w each, so just a single cable will do.

Thank you, so it doesn't make a difference for me to go with either setup? 

[Arika]

If you have no other choice then a split cable would be fine. otherwise definitely use 2 cables if you can

[Void Master]

1 minute ago, Hi P said:

Thank you, so it doesn't make a difference for me to go with either setup? 

Not that much

but its better to choose on off those recommenced configurations .

2080ti s are power hungry

[mariushm]

tldr :

 

* all connectors on video card must be used

* it's better  to use two strands with pci-e 6+2/8 pin (and use one connector from each strand) instead of single strand from psu. But it will work either way.

[Jurrunio]

12 minutes ago, Hi P said:

Thank you, so it doesn't make a difference for me to go with either setup? 

using more cables might lower potential power loss in the cables in theory, but yeah it makes no noticeable difference.

[Sirmyself]

On 12/7/2018 at 3:26 PM, COUPER MILLAR said:

Jayztwocents did a video on this a few years back. If you are not looking to hit record breaking overclocks just run the one cable with the two 8 pin connectors. Stability wise Jay saw that using two separate 8 pin cables sometimes allowed for slightly higher stable overclocks but not anything that would be noticed in daily operation. 

I was lazy... wanted to click... video was not here... had to stop being lazy so that future guys could be.

[JB780]

4 hours ago, Sirmyself said:

I was lazy... wanted to click... video was not here... had to stop being lazy so that future guys could be.

Where were you a week ago

[Sirmyself]

17 hours ago, JB780 said:

Where were you a week ago

I was a week ago man!... a week ago...

[shaz2sxy]

21 hours ago, Sirmyself said:

I was lazy... wanted to click... video was not here... had to stop being lazy so that future guys could be.

Now i'm waiting for someone to watch the video and summarise it for me....lol

 

OP - if your not O/C then single cable with 2x 8pin will be fine.

if you can then 2x cables from PSu to GFX card is better but not esential

[Sirmyself]

33 minutes ago, shaz2sxy said:

Now i'm waiting for someone to watch the video and summarise it for me....lol

 

OP - if your not O/C then single cable with 2x 8pin will be fine.

if you can then 2x cables from PSu to GFX card is better but not esential

TLDR (or TLDW) there was a difference. There seemed to have a little more stability from having two PCIe cables instead of having only one cable with a daisy-chained connector.

The difference was definitely measurable and noticeable in benchmarks but would result in quite limited performance increase in actual gaming situations.

[shaz2sxy]

14 minutes ago, Sirmyself said:

TLDR (or TLDW) there was a difference. There seemed to have a little more stability from having two PCIe cables instead of having only one cable with a daisy-chained connector.

The difference was definitely measurable and noticeable in benchmarks but would result in quite limited performance increase in actual gaming situations.

Cheers

[JB780]

6 hours ago, shaz2sxy said:

Now i'm waiting for someone to watch the video and summarise it for me....lol

 

OP - if your not O/C then single cable with 2x 8pin will be fine.

if you can then 2x cables from PSu to GFX card is better but not esential

Since my PSU only came with the daisy chain style, am I OK to use two seperate cables and just tie the daisy chain part back?

[mariushm]

1 minute ago, JB780 said:

Since my PSU only came with the daisy chain style, am I OK to use two seperate cables and just tie the daisy chain part back?

If you have only one chain of pci-e connectors, then use what you have.

Again, you don't HAVE TO use two separate chains of pci-e connectors. It's a good idea to do it if you don't mind the the extra wires and connectors but you don't need to.