Is my PSU a dud or too small?

Mercurien

Limp Gawd
Joined
Mar 16, 2002
Messages
231
I'm building a new machine:

DFI Infinity NF4X
Sempron 3300+
2*512MB Corsair Value
NEC DVD-RW
Sapphire X800 GTO
Syba PCI SATA RAID card
4*80mm fans connected to a Sunbeam rheobus
1*Seagate 80GB PATA drive (OS)
6*Seagate 250GB SATA drives
Antec TruePower 550W
Windows Server 2k3 R2

Now the DVD drive is almost never recognized by the bios when the machine boots up (doesn't show up on the "Detecting IDE Drives" screen). When the machine boots to Windows, the drive shows up fine. If I restart the machine from Windows, the drive gets detected fine. This isn't that big of a deal.

Now the system has a hell of a time trying to boot up with all 7 hard drives hooked up. (PATA and DVD attached to IDE 0, 4 SATA drives attached to the 4 headers on the mobo IDE 2-5, 2 SATA drives attached to the PCI card). The drives all click and sound like they're trying to spin up.

The system will boot just fine if I have up to 2 of the SATA drives connected. When you connect a third drive and try to power on, it sits at the "Detecting IDE Drives" for a bit, the hard drives click, then finally spin up after a few seconds and everything is good. I can restart Windows (not power down) and the drives get recognized instantly (all of them, including the DVD) and Windows boots right up.

Attaching a 4th SATA drive will cause all the drives to click and one by one they slowly spin up and the machine boots. I can turn off all of the fans completely on the rheobus and it the drives will spin up ok. If I turn on the fans, the drives will sound like they're spinning up for a second and stop then spin up again, over and over.

Attaching the 5th and 6th SATA drives will leave the machine stuck at the Detecting IDE Drives screen and the drives clicking.

I can go into the bios with 2 of the SATA drives attached and the bios reads the 12V line fluctuating between 10.6V and 12.9V. I measured the 12V line with a DMM on one of the extra power connectors and it stayed pretty steady at 11.9V. Now when the hard drives were trying to spin up and click, the DMM voltage would dip down to about 11.5V right when the drive would click and stop spinning up.

If I pull all of the SATA drives (leaving just the DVD and the PATA drive), the system will post just fine (except it doesn't see the DVD drive in the bios) and go to the loading Windows screen. As it's loading, I can hear the drive spin down completely and the machine powers off a couple of seconds later. If I attach at least one of the SATA drives, then the machine boots into Windows normally. Without this weird power down phenomenon.

Every once in a while I'll press the power button and hear the drives trying to spin up and the fans turn on, but the power LED doesn't turn on, there is no post beep, and the monitor is black. I have to hold the power button in for 5 secs to turn the machine off.

It really sounds like my power supply is the culprit, but I'm not sure if it's a dud and I should exchange it or if it's just too small. Without the 6 SATA drives, my system isn't very power hungry. I didn't think the 6 drives would take that much more power. Seagate lists each drive when active as using less than 13W. Now I know they'll take more when they're spinning up (Seagate lists 2.8A draw on the 12V line), but the TruePower 550 has two 12V rails at 19A each. They're also not all spinning up at the same time.

I am concerned about the crazy voltage readings in the bios, the lack of DVD detection, and the PATA drive spinning down during Windows booting without another SATA drive connected. These things lead me to believe that the PSU might be bad. Any second opinions?
 
Simply because you can change the symptom by changing the speed of your fans tells me that the problem is a bad 12V rail on the Antec PSU.

I would think that PSU can handle it. I've seen that PSU used in a lot more viscious builds. So it may be just a dud.
 
I have 5 drives..on a NeoPower480..and it boots fine. You probably just got a dud. RMA it/exchange/replace it.
 
I still think that people might be underestimating what a 550 watt PSU can do. Hell, my computer barely takes up 200 watts of power...
 
Digital Volt meters are cheap and so are PC = PSU testers. SOME pc rapair shops well tested it for free or small fee.
 
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