PSU rail ampres confusion

devavictrix

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Nov 30, 2014
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I have an old Dell sc1430 server that I use as a desktop with windows 8. It works great except it is fussy with graphics cards.

Lots of people (but not all) have had success with the BFG 8800gt so I bought one second hand. I cut the card down so it fitted in the x8 pci-e slot and it boots up and shows the dell splash screen and BIOS etc. But as soon as it tries to boot into windows or from a usb stick it restarts.

I believe the card requires 24a on the 12v rail. My PSU has 4 12v rails, each with 16a. Could it be that my psu isn't feeding enough power to the card?

I noticed on my scsi pci-e card that pins a2 and a3 are joined, as are b1,2 and 3. All these pins are 12v pins. I have read that you can join 12v rails so that you can bump up the ampres. I wouldn't have thought an scsi card would need stacks of power but by joining these pins is the 12v rail supplying a multiple of ampres to the card.... and is it worth trying on my sawn up and almost for the bin 8800gt?

Thanks for any help
 
Solution
i see that the card uses about 105 watts which is only about 8.75 amps on the 12 v rail so you should be fine there on a 12 amp rail.

will it boot up and run with another unmodified card installed? could be the card just does not like being surgically altered.

Math Geek

Titan
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i see that the card uses about 105 watts which is only about 8.75 amps on the 12 v rail so you should be fine there on a 12 amp rail.

will it boot up and run with another unmodified card installed? could be the card just does not like being surgically altered.
 
Solution