My Antec SL400... Only 18A on 12v Rail?

[edro]

Antec SL400 Specs

I got a new EVGA 7800GS AGP video card, and after playing for a while, my computer shut down instantly... like a power surge.

I think it was the overload protection of the power supply.
It has only done it once though.

I was looking at my PSU specs and it looks like my 12v rail is only 18A.
That seems pretty low doesn't it?

I have:
AMD 64 3000+
1gb DDR
3 HDDs
3 80mm Fans
7800GS AGP
SBLive PCI

Do you think I need a better PSU?

Online calculators estimate it at 275W.

I will use my Kill-A-Watt to see for sure when I get home.

 

[jonnyGURU]

Yep. You have one 18A +12V rail and the unit is crap to start with.

Enjoy!

 

[edro]

My Kill-A-Watt says it is consuming 190W under load (275VA, /w .70 Power Factor).

I don't know if that Power Factor is calculated or measured on the Kill-A-Watt though.

Either way, even using the VA maximum, it is only showing 275W.

Do you think the problem could be the undersized 12V side?
It has only powered down once, but I know that people who have upgraded to these newer video cards have needed to upgrade their PSU as well.

 

[myocardia]

Originally posted by: edro
Do you think I need a better PSU?

Yep, that's definitely your problem. If you want to make sure, just unplug both of your extra hard drives' molexes, plus all three 80mm fans, and try it again, with the case side panel removed, so you don't overheat.

 

[SparkyJJO]

Originally posted by: edro
My Kill-A-Watt says it is consuming 190W under load (275VA, /w .70 Power Factor).

I don't know if that Power Factor is calculated or measured on the Kill-A-Watt though.

Either way, even using the VA maximum, it is only showing 275W.

Do you think the problem could be the undersized 12V side?
It has only powered down once, but I know that people who have upgraded to these newer video cards have needed to upgrade their PSU as well.

Yes, the older antecs had the stronger 5V rail which nowadays isn't used near as much as the 12V rail. If you had a more modern 400W PSU with the emphasis more towards the 12V rail then you'd have been fine power-wise. Now, that PSU also has a crap cap issue, so not a bad idea to upgrade now either.

But when you do upgrade, if you plan on pitching the PSU, don't - PM me first.

OT: fellow Ohioan I see I'm about an hour north of you in the Mansfield area. Well, I'm going to college in Akron but home is at Mansfield.

 

[IEC]

Originally posted by: edro
My Kill-A-Watt says it is consuming 190W under load (275VA, /w .70 Power Factor).

I don't know if that Power Factor is calculated or measured on the Kill-A-Watt though.

Either way, even using the VA maximum, it is only showing 275W.

Do you think the problem could be the undersized 12V side?
It has only powered down once, but I know that people who have upgraded to these newer video cards have needed to upgrade their PSU as well.

Hard to measure AC current draw correctly without expensive equipment.

Your 18A on the +12V and the generally crappy build quality of SL series PSUs is probably why you got the overload. *But* if you haven't been able to duplicate the problem and it's not causing other issues you *could* continue using the unit until you can completely overhaul/upgrade your system.

At least it's not like a Raidmax/Powmax/cheap Ultra which will blow your system up

My recommendation is to get a PSU with at least 32A on the +12V rail from a recommended series/manufacturer on jonnyGURU's forum list of recommended PSUs. This will ensure that your PSU will be good for upgrades as well. The more amperage on the +12V rail, the better in general. Most modern PCs draw the most wattage from that rail.

 

[jonnyGURU]

Originally posted by: edro
My Kill-A-Watt says it is consuming 190W under load (275VA, /w .70 Power Factor).

I don't know if that Power Factor is calculated or measured on the Kill-A-Watt though.

Either way, even using the VA maximum, it is only showing 275W.

Do you think the problem could be the undersized 12V side?
It has only powered down once, but I know that people who have upgraded to these newer video cards have needed to upgrade their PSU as well.

Assuming the Kill-A-Watt is correct, you still don't know how much of that is on the +12V rail. I wouldn't say a 400W wouldn't be adequate for your build. I'm only saying that THAT 400W isn't adequate for your build.

 

[tomoyo]

You really have an undersized and outdated psu. Your psu is designed for ATX 1.3, which has far less 12v rail power. Getting a moderate 350-400w psu with modern ATX 2.2 design would suit you just fine in this case. The main key is having 300W of 12v power.