Quick question about PCIe cables

[Brandont7]

Hey! Got a Corsair RM850e and it comes with 2 6+2 split cables

 

https://www.corsair.com/ww/en/Categories/Products/Power-Supply-Units/RMe-Series-Fully-Modular-Low-Noise-ATX-Power-Supply/p/CP-9020249-WW

 

looking at getting a 7900xtx (TUF gaming)

 

has 3 8pins would it be okay to just use the cables that come with the PSU?

 

many thanks

[RONOTHAN##]

Just now, Brandont7 said:

has 3 8pins would it be okay to just use the cables that come with the PSU?

 

Yes, that's fine. It only theoretically becomes an issue when you start looking at low end PSUs with thinner cables, but that's not the case on the RM850e. 

[Brandont7]

Just now, RONOTHAN## said:

Yes, that's fine. It only theoretically becomes an issue when you start looking at low end PSUs with thinner cables, but that's not the case on the RM850e. 

Okay great! Thank you for clearing that there is a lot of conflicting information online

 

so would I just leave the unused 6+2 just hanging there?

[RONOTHAN##]

2 minutes ago, Brandont7 said:

Okay great! Thank you for clearing that there is a lot of conflicting information online

 

so would I just leave the unused 6+2 just hanging there?

It is considered best practice to use 3x8 pin cables rather than the pigtails, but it's not really necessary. I've used the pigtails on my BIOS modded 6900XT before, it was pulling over 500W (much more than the ~450W the 7900 XTX can top out at with the power sliders maxed out) with no issues with the cables. It's theoretically better, but practically it doesn't really make a difference outside of the high power dual 8 pin cards (3090 XC3, for instance) and some Nvidia GPUs with weird power management behavior (1080 Tis, for instance, are something like 3% slower when using the pigtail for whatever reason). 

 

Just leave the extra pigtail hanging out, maybe zip tie it out of the way if you care about cable management. 

[Brandont7]

4 minutes ago, RONOTHAN## said:

It is considered best practice to use 3x8 pin cables rather than the pigtails, but it's not really necessary. I've used the pigtails on my BIOS modded 6900XT before, it was pulling over 500W (much more than the ~450W the 7900 XTX can top out at with the power sliders maxed out) with no issues with the cables. It's theoretically better, but practically it doesn't really make a difference outside of the high power dual 8 pin cards (3090 XC3, for instance) and some Nvidia GPUs with weird power management behavior (1080 Tis, for instance, are something like 3% slower when using the pigtail for whatever reason). 

 

Just leave the extra pigtail hanging out, maybe zip tie it out of the way if you care about cable management. 

How odd didn’t know that!

 

thanks a lot for the info, would you think it’s worth getting 3 8pin cables or not worrying about it really as it should be fine

[RONOTHAN##]

1 minute ago, Brandont7 said:

How odd didn’t know that!

 

thanks a lot for the info, would you think it’s worth getting 3 8pin cables or not worrying about it really as it should be fine

If you had the cable, I'd say use it, but since you don't I wouldn't bother personally. You won't get any benefit from it, so why bother? Only reason I see for you to do it in your case is if you don't like the aesthetics of the pigtail, which admittedly 3 8pins do look better than the pigtail and a standalone one. 

[Brandont7]

6 minutes ago, RONOTHAN## said:

If you had the cable, I'd say use it, but since you don't I wouldn't bother personally. You won't get any benefit from it, so why bother? Only reason I see for you to do it in your case is if you don't like the aesthetics of the pigtail, which admittedly 3 8pins do look better than the pigtail and a standalone one. 

Yeah that’s definitely true!

 

but thanks again for the info it’s saved me spending more time looking at loads of pointless posts about PCIe cables