980 ti power lead question

[fastboy]

so I have just got a 980ti gigabyte wf3 edition and it has 2 x 8 pin connectors.

my psu is a modular evga 550gs gold with 2x vga outputs on it,unfortunately I only have 1 8pin into 2x8 pin lead for the psu,will this be ok for the 980ti or will I need to source another 8 pin lead?

thanks
david

 

[lurkio]

The extra 2 wires are ground return

I hacked a 2 pin cable together using bits from a damaged power supply and soldered them onto a 4 pin molex gound pin

 

[Dirk Diggler]

so I have just got a 980ti gigabyte wf3 edition and it has 2 x 8 pin connectors.

my psu is a modular evga 550gs gold with 2x vga outputs on it,unfortunately I only have 1 8pin into 2x8 pin lead for the psu,will this be ok for the 980ti or will I need to source another 8 pin lead?

thanks
david

You should have received a Molex to VGA lead with the card. Use that instead of the B.A. Baracus approach.

 

[fastboy]

nope not got one of those,will the 8 into 2x8 be enough for the 980 ti tho?
if not will I need an evga specific 8-8 lead?

 

[five8five]

The original spec of the PSU is two modular PCIE cables each with two 6+2 pin connectors to support SLI & Crossfire so you should be fine using one cable for a 980Ti.

 

[fastboy]

ok thankyou

 

[liveid]

The original spec of the PSU is two modular PCIE cables each with two 6+2 pin connectors to support SLI & Crossfire so you should be fine using one cable for a 980Ti.

Dont agree, depends on the reliable psu power delivery via one cable AND the card has power averages and peaks that could cause issues.

I'm sure it would boot but if it works (some card detect bad power) it or the psu is more likely to fail under heavy loads sooner or later.

Quick calc based on average of 250w ish for the ti, less 75 w from the board leaves 175w from the 8 pin on its own, atx recommendation is for 150w per 8 pin, so your short with just 1 8 pin connected


either get the evga cable or use 2 molex to 8 pin gpu which is good for another 120w and has some headroom provided the psu is happy

 

[liveid]

The extra 2 wires are ground return

I hacked a 2 pin cable together using bits from a damaged power supply and soldered them onto a 4 pin molex gound pin

1 is ground return the other is called sense b for connector detection but is actually a ground, apparently adding 2 extra grounds allowed the 3 + power leads from the usual 6 pin connector to carry more current more reliably than adding another + and ground pair. The sense b tells the psu it can deliver more current and the card its getting the power it was designed for (assuming they implemented tests)