Powering 2900CF.What are my options? - Overclock.net

gunner14 · 03-10-08

So I picked up my first 2900xt back in April 07 with the intention to go crossfire eventually. Few days ago I grabbed a second 2900xt on ebay for $150. I'm using an OCZ GameXreme 700w PSU at the moment and I dunno if I can power both cards with that. It doesn't have enough PCIE connectors either. It has 72A across 4 12v Rails and 2 6pin pcie connectors.

http://www.newegg.com/Product/Produc...82E16817341002

(Option 1 Preference)Even if i got the extra pcie connectors, would 700w be enough? I've done a bit of testing and the entire CPU maxes out at 350w under full load. That leaves another 300W that I'm not coming close to using. I don't OC gfx cards much either. I could just buy molex-pcie adapters for the 2nd card.

(Option 2)How about using a 2nd PSU just for the 2nd card? Is that feasible? Theres definetly space in my case for it. I have this Cooler Master PSU sitting in a server:

http://www.newegg.com/Product/Produc...82E16817171018

(Option 3)Just bite the bullet and get a new PSU and try to sell the OCZ on ebay? I really don't want to shell out $250 for a new psu. I don't have enough rep to sell here so I'd probably end up stuck with the OCZ even If i did buy a new psu.

Any recommendations under $200?

ATI is really pissed me off with these 8 pin connectors and 10,000 Watt gfx cards. I'd appreciate any advice.

HauntSheep · 03-10-08

Quote:

ATI is really pissed me off with these 8 pin connectors and 10,000 Watt gfx cards

Wel the 8800 Ultra needs 2 8 pin power connectors also, high power graphics cards need...high power being supplied to them, a V12 Engine isnt going to use less fuel than a standard 4 cylinder car is it, no, its going to use a lot more

DuckieHo · 03-10-08

Quote:

Originally Posted by HauntSheep

Wel the 8800 Ultra needs 2 8 pin power connectors also, high power graphics cards need...high power being supplied to them, a V12 Engine isnt going to use less fuel than a standard 4 cylinder car is it, no, its going to use a lot more

No, it doesn't. The Ultra uses two 6-pin PCIe plugs.

gunner14, your PSU only has 56A on the +12v. 700w should be enough to power both the cards. I would use PCIe to fill the 4 PCIe plugs. The 2900xt really doesn't need a 8-pin PCIe plug. I would then just bridge the 6-pin to 8-pin. However, the OCZ/FSP PSU is known to exhibit ripple at higher loads.

HauntSheep · 03-10-08

Quote:

No, it doesn't. The Ultra uses two 6-pin PCIe plugs.

I cant count =[

gunner14 · 03-10-08

Quote:

Originally Posted by HauntSheep

Wel the 8800 Ultra needs 2 8 pin power connectors also, high power graphics cards need...high power being supplied to them, a V12 Engine isnt going to use less fuel than a standard 4 cylinder car is it, no, its going to use a lot more

Indeed, but when I bought this PSU early last year I didn't quite expect I'd need 8 pin connectors a few months later.

**alexgheseger** · 03-10-08

Well, with the amperage on your PSU, i'd say you should be safe. 2900's don't suck as much power as people tend to think.

DuckieHo · 03-10-08

680w/12v = 56.67A. However, some of that is needed by the +3.3v and +5v rails.

pbpenguins412 · 03-10-08

Go with Option 1. Your PSU has plenty of power.

linskingdom · 03-10-08

Here is the requirement for 2900XT CF with loaded machine from ATI. So, based on what you have, 700W may make a cut.

**grunion** · 03-10-08

You only need 8 pins if you wanna oc with overdrive.

I would upgrade, PCP&P or a nice Silverstone.

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Powering 2900CF.What are my options?

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