1 PCIE power cable vs 2

[EndoHash]

I currently have my 2080 Super powered off of one PCIE power cable, with 2 6+2 pins

 

Is this bad practice? Will I see more performance using 2 separate PCIE power cables coming from the PSU? 
 

My psu is a Corsair RM750 80+ Gold 750W

[BlueChinchillaEatingDorito]

1 minute ago, EndoHash said:

I currently have my 2080 Super powered off of one PCIE power cable, with 2 6+2 pins

 

Is this bad practice? Will I see more performance using 2 separate PCIE power cables coming from the PSU? 
 

My psu is a Corsair RM750 80+ Gold 750W

Nope, nothing wrong with that. 

[Ankerson]

11 minutes ago, EndoHash said:

Is this bad practice?

 

With GPUs that draw more than 225W it's generally better practice to use 2 separate cables.

 

Could run into stability issues etc depending using one cable.

 

11 minutes ago, EndoHash said:

Will I see more performance using 2 separate PCIE power cables coming from the PSU? 

 

It's possible depending on the card and power draw...

[BlueChinchillaEatingDorito]

8 minutes ago, Ankerson said:

With GPUs that draw more than 225W it's generally better practice to use 2 separate cables.

 

Could run into stability issues etc depending using one cable.

 

 

It's possible depending on the card and power draw...

Not necessarily. Unless you're using really cheap PSU harnesses that are overrated for what they can handle, then yes you can run into issues as the cables begins to burn and fry itself under the intense load. In terms of performance, the card will draw whatever power it requires from the PSU and the PSU will provide it. The harness itself will not limit the amount of power that travels through it (again... unless it starts going up in smoke/flames) because it's just a copper wire. With modern PSUs, all you should really care about is the total listed capacity of the 12v source of your unit. If your PSU can't provide the juice that your card demands, using multiple harnesses isn't going to change much of anything.

[Ankerson]

13 minutes ago, BlueChinchillaEatingDorito said:

Not necessarily. Unless you're using really cheap PSU harnesses that are overrated for what they can handle, then yes you can run into issues as the cables begins to burn and fry itself under the intense load. In terms of performance, the card will draw whatever power it requires from the PSU and the PSU will provide it. The harness itself will not limit the amount of power that travels through it (again... unless it starts going up in smoke/flames) because it's just a copper wire. With modern PSUs, all you should really care about is the total listed capacity of the 12v source of your unit. If your PSU can't provide the juice that your card demands, using multiple harnesses isn't going to change much of anything.

 

 

NOT REALLY....

 

Seen it a lot over years were someone has had stability issues and were using a daisy chained cable and it was fixed by switching to two separate cables.

 

Normally with high powered GPUs..... Not so much with the mid range and below.... They don't pull enough power to make a difference.

 

PSUs didn't really matter as most of them that I saw them using were good high quality units.

 

Used to see it a lot over on Toms Hardware, and I do mean one hell of a lot, like pretty much daily and they have a VERY active PSU section over there.

 

Not on TH anymore due to an issue with some MOD that happened to be an AMD fanboy and was in denial about their CPUs bottlenecking high end GPUs at 1080P.... Yeah I know...... Well known issue.... But anyway I was banned..... 

[jonnyGURU]

It saddens me that primary schools do not teach basic electronics principals, like Ohm's law. 

 

While the single cable can "support" that much power, the current produces resistance that can cause the voltages to drop and this will cause stability issues. 

 

 

[Ankerson]

1 minute ago, jonnyGURU said:

It saddens me that primary schools do not teach basic electronics principals, like Ohm's law. 

 

While the single cable can "support" that much power, the current produces resistance that can cause the voltages to drop and this will cause stability issues. 

 

 

 

Yes, EXACTLY as you know because that's what you do for a living....

 

But you know, it's the internet... 

 

 

 

[BlueChinchillaEatingDorito]

10 minutes ago, Ankerson said:

 

 

NOT REALLY....

 

Seen it a lot over years were someone has had stability issues and were using a daisy chained cable and it was fixed by switching to two separate cables.

 

Normally with high powered GPUs..... Not so much with the mid range and below....

 

PSUs didn't really matter as most of them that I saw them using were good high quality units.

If you're daisy chaining stuff you're begging for trouble... This is why those Molex or SATA to PCIe adapters were just a terrible idea. Those harnesses were not designed for the power draw GPUs required. So as a result over time you had those Molex or SATA connectors that fed power to the GPU melt or in some cases the wiring to melt. Then you had the issues where the 5v rail that powered SATA and Molex just didn't have the capacity that was demanded. Storage devices just don't pull as much power as GPUs. 

 

If you're sticking with the harnesses that came with the PSU and don't add any additional adapters to try to force your way through, you would not run into any issues. 

 

I used a molex to P4 CPU power adapter myself years back, yea thing was cheaply made and yea that thing caught fire.