psu dual 12v rails

[aidy1972]

I just installed a 550 ti and am getting black screen of death during gaming. Other research has pointed to either overheating or not enough power.

I have a 700watt PSU with dual +12v rails. Specification says 21A on them. However the card demands 24A

I don't fully understand the whole Amperage thing here. Does 2x21A give me around 40A or is it just putting out (in theory) 21A?

I'm using a converter for the card's 6 pin that requires 2 Molex. I'm not certain if its possible to use a molex from both or 1 rail? The cables from the molex seem to originate from same place and it appears that there's another bunch of cables coming from another position off the psu. Would I be better using power from 2 separate cable bunches? Or is it not going to make a difference as my amperage is already too low?

 

[ihog]

Please post the make and model of the PSU.

 

[aidy1972]

http://www.aone.co.uk/ProdInfo.ASP?ProductID=2457

That is close if not exact same model. Forget to mention that the previous card didn't required a 6 pin plug and didn't have any trouble. The card before that did and it used to suffer same trouble.

http://www.asrock.com/mb/NVIDIA/K10N78FullHD-hSLI%20R3.0/ motherboard using a phenom 9850 quad core 2.5ghz black edition

 

[ihog]

Why are you using the molex adapter when there is a 6-pin plug coming from the PSU?

 

[aidy1972]

The PSU came with an adaptor (Older model than one shown but identical stats across the board) there isn't one connected directly to the Power Supply Unit.