Resolved Is a PSU with dedicated 6pin video card connectors preferable?

My second PC had a 500 watt PSU and recently I upgraded the video card to a HD6770 which has a separate (6 pin) power socket. The power supply did not have any 6 pin plugs however the video card came with a 6 pin to 4 pin molex adaptor which I used. The video card suggested a minimum 450 watt psu (I had a 500 watt psu).
A few weeks after installing the video card the power supply failed. This could well have been coincidental.
I considered replacing the psu with a 550 watt one however the salesman suggested that as I have a video card which has a separate (6 pin) power connector that I should purchase a 650watt psu which has separate 6pin video card plugs. The 650 watt psu is nearly twice the price of a 550 watt psu.

Is it preferable to have a psu with dedicated 6pin video card sockets or is using adaptors perfectly ok?

 

Your power supply has to supply the correct voltage & current. Whether its done over a dedicated 6 pin socket or is delivered by adaptor doesn't make any difference. If the power supply rail can handle the current, don't worry about it.

 

Thanks rsinfo
I guess I need to add up the power requirements (watts) of everything I have connected to each PSU output and compare to the rated output on each.
This begs another question -
The voltage on the molex plugs is 12 volts as is the voltage on other plugs yet they have separate leads. But does the PSU output complete separate voltage/watts for each or do they share the same 'rail'?

 

Read the info here:
http://www.journeysystems.com/support/calculator/
It talks about the rails.

 

Most of the power supplies have common rails for different voltages ie. 12V+ would have a separate rail, 12V- would have a separate rail & so on.

If some power supply uses different rails for the same voltage, it would state that upfront & charge a premium for that.

 

Thanks again,

I have now purchased a 650watt PSU and installed it (I guess "size matters" - better to have spare capacity).

I have now found that the IDE to SATA adaptor (the second drive is a PATA drive and the MB doesn't have an IDE port) also seems to have died.

I checked that the power connector to the adaptor for correct voltages to ensure it was the adaptor and not power supply.

I wonder if the IDE>SATA adapator failing had anything to do with the original PSU failing. The back of the adaptor also seems to have some corrosion on the PCB around where the pins for the SATA socket are soldered to the PCB which I did not notice when I installed it just 4 weeks ago (it was brand new) - so it is going back to the PC shop for a replacement under warranty.

 

Its better to be safe than sorry. A power supply which is rated more than the minimum requirement is much better, though its efficiency would be a little low [in general power supplies perform best at around 75-85% load]. But in your case, you have chosen a power supply which is most efficient for your load [650 x 75% = 487 W]

 

Thanks