7970 PSU Question

[ruhtraeel]

Hey,
So it turns out my 1050W OEM PSU doesn't have enough 4 pin molex's to be able to use all the 2 x 4 pin molex to 8 pin adapters that came with my 7970 (My PSU has three 4 pin molexes).

Could I get away with just plugging one molex for one of the adapters?

This is my power supply:
http://www.plugloadsolutions.com/psu_reports/DELTA%20ELECTRONICS-DPS-1050CB%20A-1050W-Report.pdf

Thanks!


EDIT: Also just noticed, the 7970 is giving me the same if not worse performance in Skyrim than my 5870's did lol, I have a lot of mods running with an ENB, is this normal?

 

[Freddy1765]

Don't you have any PCI-e power connectors? Pretty sure using Molex adapters is a bad idea.

 

[ruhtraeel]

Don't you have any PCI-e power connectors? Pretty sure using Molex adapters is a bad idea.

I don't have any 8 pin connectors I could use. I think Sapphire knew that most people wouldn't have enough so they bundled them with the card.

 

[Stuka87]

I am confused. You say you don't have enough power adapters to use the card, but then state that you are using the card. Which is it?

If you are trying to use the card without all the power adapters, then performance will be terrible.

Using the molex adapters is fine if the rail they are plugged into has enough power.

 

[ruhtraeel]

I am confused. You say you don't have enough power adapters to use the card, but then state that you are using the card. Which is it?

If you are trying to use the card without all the power adapters, then performance will be terrible.

Using the molex adapters is fine if the rail they are plugged into has enough power.

I forgot to mention that as of now, I have a 750W OEM PSU plugged in there. The 750W one has an abundance of molexes, so I was able to plug all the 2x 4 pin molex to 8 pin adapters.

However, the problem with the 750W PSU is that it seems to have a different shut-off mechanic; hitting the power button when using the 750W PSU is plugged in does nothing, but the 1050W (which is newer) will power on and off properly.

I think I have a 6 pin to 6 + 2 pin adapter, would that work, if I was using an 8 pin and a 6 + 2 pin (similar to the regular 7970)?

I also have a 2x 4 pin molex to 6 pin, could I just plug a 6 pin connector into an 8 pin slot?

It's sort of silly that Sapphire doesn't package 2 x 6 pin to 8 pin adapters for this card.

 

[Stuka87]

I forgot to mention that as of now, I have a 750W OEM PSU plugged in there. The 750W one has an abundance of molexes, so I was able to plug all the 2x 4 pin molex to 8 pin adapters.

However, the problem with the 750W PSU is that it seems to have a different shut-off mechanic; hitting the power button when using the 750W PSU is plugged in does nothing, but the 1050W (which is newer) will power on and off properly.

I think I have a 6 pin to 6 + 2 pin adapter, would that work, if I was using an 8 pin and a 6 + 2 pin (similar to the regular 7970)?

It's sort of silly that Sapphire doesn't package 2 x 6 pin to 8 pin adapters for this card.

The reason they dont provide a 6pin to 8 pin adapter is because it would defeat the purpose of using an 8 pin connector on the GPU. The 8 pin is there because of the required power draw. You risk exceeding the rated current of the 6 pin connector/wires by plugging it into an 8 pin.

Its very important that you do not exceed the current draw of the wires being used, and that the 12V rail you are connected to has enough current available.

I am trying to figure out why a true 1050W PSU has so few connectors. I can't find anywhere that states just how much current each rail can output.

 

[ruhtraeel]

The reason they dont provide a 6pin to 8 pin adapter is because it would defeat the purpose of using an 8 pin connector on the GPU. The 8 pin is there because of the required power draw. You risk exceeding the rated current of the 6 pin connector/wires by plugging it into an 8 pin.

Its very important that you do not exceed the current draw of the wires being used, and that the 12V rail you are connected to has enough current available.

I am trying to figure out why a true 1050W PSU has so few connectors. I can't find anywhere that states just how much current each rail can output.

From what I've seen, a lot of 7970's have 2x 6 pin to 1x 8 pin adapters, since one 6 pin = 75W, and one 8 pin = 150W.

I'm really not sure why my 1050W PSU has so few molexes; it's one pulled from an HP XW9400 workstation. It has two dedicated 6 pin connectors, so if I had a 2x 6 pin to 1x 8 pin, my problems would be solved.

My power supply only has three 4 pin molexes, but it has around 10-12 SATA power connectors.


http://www.aliexpress.com/item/H-P-...S-1050CB-Workstation-1050W-PSU/553323227.html


EDIT:
I found my solution. I'll get one of these:
http://www.memoryexpress.com/Products/MX32414