No 8-pin pci-e on my power supply... should I use 6 pin or 2 molex?

[Enhanced_Interrogator]

Hey guys, I've got an old p4 agp system, I just got the sapphire hd 3850. Right now I'm using the two molex to 8-pin pci-e adapter. I've had a couple voltage drops on the 12v rail, but I'm not 100% sure if it was caused by the card.

Anyway, I'm wondering what y'all think would be more stable. I've read that I can plug the 6-pin pci-e into the 8-pin connecter and still use the card. Would that be more stable under heavy graphics load thatn the 2 molex? Would using a 6 to 8 pin adapter be significantly more stable than the other two options?

 

[cjl]

What PSU do you have?

 

[Enhanced_Interrogator]

Antec TP3-550, it has two pci-e 6-pins.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817371002

There are posts on the forum with people saying the have used a 6 pin connector with no issues. Others have used 2 molex and had no problems. I'm just curious as to which would theoretically be more stable in an 8-pin gpu.

Edit: And when I said voltage drops, I don't mean I had a system crash, just that I got a warning from my monitoring software.

 

[Kari]

wait what? you have a agp 3850 that has 8pin pcie power connector..... 0_o

 

[Enhanced_Interrogator]

yep

http://www.newegg.com/Product/Product.aspx?Item=N82E16814102730

It's a monster card that is getting bottlenecked by my CPU and the AGP bus, but it's a pretty good deal at $88. This card lets me play new games like FEAR 2 at max detail settings (I usually have to hold back on AA). I figure this thing will keep me afloat for a couple years to play most of the games I'm interested in (minus SupCom 2), and I'll build a nasty new system from the ground up then.

 

[coozie7]

Use the PCI-E 6-8 converter, the molex plugs are not really intended to drive high power devices and some PSU's restrict the power they send to such lines anyway.

 

[Enhanced_Interrogator]

Thanks coozie. So what are the advantages of using the 6-8 adapter versus just plugging the 6-pin straight in (which is possible with this card)? Will the adapter allow more voltage to pass through the line? Just curious because they didn't include a 6-8 adapter, so I'd have to buy one.

 

[Kari]

yep

http://www.newegg.com/Product/Product.aspx?Item=N82E16814102730

that's sick, all the agp cards I've had only had 4pin molex for extra power. lol guess that card really needs the extra juice

 

[coozie7]

@ Enhanced_Interrogat: Must be the effects off too much overtime, I misread your post. AFAK it'll be OK to us the 6 pin directly, the extra two pins are returns, not live voltages.