Did I get the wrong PSU?

Drooling Iguana · Post by **Drooling Iguana** » 2007-01-22 11:25pm

I'm putting together a new computer but I've run into a bit of a problem. I'm trying to plug the main power cable from my PSU into my motherboard, but they appear to be different sizes. The plug on my motherboard has four more pins (two rows of two each) than the plug from my PSU does. The plug still fits in fine, with all the square and six-sided pins lining up with their counterparts on the motherboard, but with the extra four pins left empty on one side.

Is this a problem? Does this mean that my PSU and motherboard are incompatible in some way, or are there just some pins left over on the board for future expansion or somesuch?

Uraniun235 · Post by **Uraniun235** » 2007-01-22 11:59pm

A 20-pin ATX power supply should be compatible with a 24-pin ATX motherboard.

Ace Pace · Post by **Ace Pace** » 2007-01-23 12:00am

It means your PSU is of an older specification then the motherboard.

In most cases, this dosn't bring any problems to computer stability, but if it's a high end computer and is heavily stressed alot(like gaming), you might see some instability.

Drooling Iguana · Post by **Drooling Iguana** » 2007-01-23 12:14am

As long as I don't see any blue smoke.

Exonerate · Post by **Exonerate** » 2007-01-23 04:28am

Make sure the #1 pins are aligned correctly or nasty stuff could happen. There are 20 to 24 pin adapters out there fairly cheap. As long as your system isn't too power hungry, you should be fine.

Uraniun235 · Post by **Uraniun235** » 2007-01-23 11:12am

I'm pretty sure the pins are shape-coded so that you can't insert it in the wrong way.

Exonerate · Post by **Exonerate** » 2007-01-23 02:14pm

Uraniun235 wrote:I'm pretty sure the pins are shape-coded so that you can't insert it in the wrong way.

Not always - my DFI mobo's pins were all rectangular, so you could insert them in any direction you wanted to. And since you're putting a 20-pin to a 24-pin, the latch thing that locks the thing in place doesn't always match up either.

Chris OFarrell · Post by **Chris OFarrell** » 2007-01-23 06:25pm

Yeah 20 to 24 pin connectors are cheap as chips, but have a careful look at the power supply before you go too far.

If this is a gaming rig and its less then 400 watts (and have a GOOD look at the +12V line to make sure its also got a solid amount of energy) I'd just skip it and buy a new quality power source.

Drooling Iguana · Post by **Drooling Iguana** » 2007-01-23 11:23pm

It's 450W, and both the cable and the plug are shape-coded.

Post by **Beowulf** » 2007-01-23 11:35pm

Wattage doesn't matter too much. Most computers don't manage to use more than 200W. My last computer only had a 250W PSU. It had a X800 XT vid card in it. More important is the quality of the PSU (how heavy is it?), and current sourcing ability on the +12V rail (you should have at least 18 amps for a modern computer).

Drooling Iguana · Post by **Drooling Iguana** » 2007-01-24 12:02am

The +12V rail is exactly 18 amps. Not sure about the weight, as I've never removed it from the case.