Stupid question of the day - GPU power content

Blood&IceCream · 15 Feb 2013 at 12:57

just received my monster GPU for a new build

- it requires 2 x 8pin connectors

i do have two spare cables for this (on the right), but I also have a two headed 8 pin cable (on the left) - am i okay in using the two headed cable?

PSU is a Corsair AX760i and the GPU is a <gulp> GTX690... tis on offer this week.. thats my excuse...

ps - the couriers OCUK use are excellent - every single delivery is always spot on time to the minute :cool:

whyscotty · 15 Feb 2013 at 16:56

DO NOT USE THE DOUBLE 8 PIN :eek:

Also the only stupid question is the one you don't ask

Blood&IceCream · 15 Feb 2013 at 17:44

don't worry - i've just fired it up with the two separate cables as i was unsure, and currently loading up the drivers as i type this on a different machine

thanks for the reply

Space Monkey · 15 Feb 2013 at 18:15

whyscotty said:
DO NOT USE THE DOUBLE 8 PIN

Also the only stupid question is the one you don't ask

Out of curiosity, why not the double header cable? I'm guessing to split the rails? :confused:

whyscotty · 15 Feb 2013 at 19:06

Space Monkey said:
Out of curiosity, why not the double header cable? I'm guessing to split the rails?

It was just a gut feeling that the double header wasn't designed to be
used with a Gpu that draws 300watt plus.(standard 8 pin being 150watt)

Space Monkey · 15 Feb 2013 at 19:08

whyscotty said:
It was just a gut feeling that the double header wasn't designed to be
used with a Gpu that draws 300watt plus.(standard 8 pin being 150watt)

Ah right, I'm about to use a dual cable on my 670 but that's 2 6 pins, should be ok?

teenwolf · 15 Feb 2013 at 19:09

whyscotty said:
It was just a gut feeling that the double header wasn't designed to be
used with a Gpu that draws 300watt plus.(standard 8 pin being 150watt)

but surely it just uses the same 12v rail ?

whyscotty · 15 Feb 2013 at 19:13

Space Monkey said:
Ah right, I'm about to use a dual cable on my 670 but that's 2 6 pins, should be ok?

bunnox said:
but surely it just uses the same 12v rail ?

Like I said it was more of a call that the cable wasn't designed for that power draw, not that the rail couldn't provide the juice.

teenwolf · 15 Feb 2013 at 19:14

cable will handle it just fine.

whyscotty · 15 Feb 2013 at 19:38

bunnox said:
cable will handle it just fine.

So your saying one 8 pin pci-e can adequately power a 690?

teenwolf · 15 Feb 2013 at 20:38

whyscotty said:
So your saying one 8 pin pci-e can adequately power a 690?

and i am baffled again by your inadequate post.

Gregster · 15 Feb 2013 at 20:47

http://www.tomshardware.co.uk/forum/366223-15-power-connectors-coolermaster

It is not advised to use splitters but I am clueless when it comes to PSU's. I need to start swatting up on PSU's though.

whyscotty · 15 Feb 2013 at 20:52

bunnox said:
cable will handle it just fine.

whyscotty said:
So your saying one 8 pin pci-e can adequately power a 690?

bunnox said:
and i am baffled again by your inadequate post.

Your basically stating 1 X 8 pin pci-e cable can handle the power draw of a 690,

How is that a inadequate post?

Kaapstad · 15 Feb 2013 at 20:53

gregster said:
http://www.tomshardware.co.uk/forum/366223-15-power-connectors-coolermaster

It is not advised to use splitters but I am clueless when it comes to PSU's. I need to start swatting up on PSU's though.

I would not take a chance with cables when it comes to powering a GTX 690.

My 2 690s + CPU when oced can draw over 1000 watts at the wall, its just not worth it taking a chance on a dodgy cable.

whyscotty · 15 Feb 2013 at 20:59

Kaapstad said:
I would not take a chance with cables when it comes to powering a GTX 690.

My 2 690s + CPU when oced can draw over 1000 watts at the wall, its just not worth it taking a chance on a dodgy cable.

This is why I said not to use the 8 pin splitter, just didn't ring true that it's capable for a 690

Jakus · 15 Feb 2013 at 21:48

There is probably 3 feeds and 3 returns on those connectors, at 300w that's only 8 amps per wire (if it pulled the max)

As said the PSU's are generally single rail and the GFX connectors are all joined together on the board , also 8 pin connectors still only have the same 3 feeds just 2 additional returns (earths)

It should be totally fine with either setup, 2 separate cables would be better just in regard of the connectors at the PSU end not having to handle as much current...and if there is a weakness it's always connectors rather than wire

teenwolf · 15 Feb 2013 at 21:50

whyscotty said:
Your basically stating 1 X 8 pin pci-e cable can handle the power draw of a 690,

How is that a inadequate post?

its a twin cable and will be fine.
where did i say only to connect one of them

~Dockie · 15 Feb 2013 at 21:59

bunnox said:
cable will handle it just fine.

^^ if the rail can handle it, then the cable can. if your rail can supply 25amps on that slot then go for it.

Space Monkey · 15 Feb 2013 at 22:27

~Dockie said:
^^ if the rail can handle it, then the cable can. if your rail can supply 25amps on that slot then go for it.

I've got 6 rails at 30A per rail so should be ok on a 670?

~Dockie · 15 Feb 2013 at 22:33

holy cow, do you use a nuke to power your pc? :eek:

yeah, should be more than enough.