7970 Lightning, PSU Issue?

suiken_2mieu

suiken_2mieu

2[H]4U
Joined
Apr 7, 2010
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So I bought a MSI 7970 Lightning and it has 2-8 Pin Connectors. I have an Ultra 750 Watt power supply that is a little older, but I never had issues running my system with it until now.

It only has 1 8-Pin connector and 2 6-Pin connectors. I used a 6-pin to 8-pin adapter that came with the card. I can get the card to load windows, but as soon as I load 3D content, I lose Video Signal. I don't get it back until I power cycle the system. Oddly enough, If I use 2 6-pin to 8-pin adapters, I can get the card to render 3D for few seconds until I lose video signal.

I put the card into my roommates system, he has a Rosewill 700 watt PSU with the same deal, only 1 8-Pin and 2 6-Pin connectors. I use the adapter in his system and it works perfectly.

So, I'm pretty sure it's not the card. What's weird is that I'm running my 5870 at 950/1200 @ 1200mV, and the 7970 at it's own factory overclock. I tried underclocking it to stock 7970 settings, but as soon as I hit apply, it looses Video Signal.

Do you think my PSU is just not up to snuff? Again, I'm still using it to power my rig and still playing games on my 5870.
Also, I want to go Xfire, so what PSU would you recommended?

Roommates Rig:
i7-950 Stock
AMD 6870 1GB
ASUS Rampage III "Gene" Mother Board
Rosewill 700 Watt PSU
WD 500GB Sata HDD
Random Optical Drive
12GB DD3 RAM

My rig is in my signature.

My 5870
My 7970 Lightning
 
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Ultra makes pretty low end hardware. I would spend another $75 and get a nice Corsair TX 750 to protect your new $450 GPU investment.
 
That PSU is highly recommended. It's quiet, efficient, but a bit pricey. For a high end CF setup though, you don't want to skimp on the PSU.
 
$114 for a very highly regarded 750w psu is FAR from pricey.

That 850w seasoning psu is a bit overkill, but still a good choice
 
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