Low PSU voltages?

[Alex Cavnar, aka alc6379]

I'm using a cheap Arrow 500w PSU that I got off of Pricewatch. Lately, the box has been rebooting randomly.

I'm using EasyTune 4 from Gigabyte under Windows, and it's saying that my voltages are a little lower than what they need to be. Here's what it's running:

Vcore: ~1.64v
+3.3v: ~3.2v
+5v: ~4.78v
+12v: ~12.11v
+5Vsb: ~4.8-4.9v

Are these kind of low? I'm concerned about that +5v being around 4.7. I'm thinking I need a new PSU, I'm going to get a Vantec or an Antec, something of higher quality.

My CPU temps are good, I've never peaked over 45degC according to EasyTune or the BIOS, so I'm thinking that there's no issue there. I'm not overclocking, either. Here are the specs of the box:

Barton XP2500+
Gigabyte GA-7VT600 1394 motherboard
Radeon 7000 64MB dual VGA
2x256MB Geil ValueRAM PC3200
Western Digital 30GB 5400RPM hdd
Mitsumi 16x4x32 CD-RW
Swiftech MCX-462-V heatsink
3 Vantec tornado 92mm fans
2 no name 3000RPM fans
Vantec fan controller

Considering the amount of fans in this box, (Those Tornadoes are MONSTERS), think I might need to get a higher quality PSU?

[hard candy]

From a chart in MaximumPC:
1 Athlon XP= 60-90 watts (Make it 75 watts for yours)
2. Motherboard=20-30 watts
3. RAM=20 watts per 256MB=40 watts for yours
4. PCI Card=5-10 watts= does yours have a soundcard?
5. AGP videocard=20-60 watts=20 watts for yours
6. 5400 HD=5-10 watts=10 watts for yours
7. Floppy drive=5 watts= do you have one?
8.CD/DVD drive=10-20 watts=15 watts for yours
9. CPU fan=2-4 watts=3 watts for yours
10. Case fans=2-4 watts= 16 watts (4 watts for the Vantecs, 2 watts for the generics)
Total= 204 watts, very roughly.
The el cheapo PSU's will vary quite a bit in what they put out and if everything is peaking, liike on a boot-up, your wattge could jump over 300 watts in spikes.
I would get a new one, you'll have it when you upgrade in the future.

[sharth]

Yeah, but you could be limited on one or more of the rails.

I have lower ratings on all the rails on my computer, but mine works fine (now that i stuck a paperclip into the powersupply. Should be okay..

[Loki3]

Those voltage ratings look okay. However... one I learned is never trust the on-board sensors. If you have access to a multimeter by all means check the voltages manually. I once had my sensors register a 3.3 rail at around 7. I doubled checked with a multimeter and it was 3.3.

Power supplies ain't all about the watts. Determining quality of a power supply via watts is a little like determing how fast a car can run a 1/4 mile by engine horsepower measured at the flywheel. There's many more variables that go into it such as, air temp, humidity, drivetrain, tires, etc.

Check out these threads on the overclocker's forum, they'll help you determine the output of your PSU:

http://www.ocforums.com/showthread.php?threadid=252752

and

http://www.ocforums.com/showthread.php?threadid=62822

Hope this throughly confuses you and then eventually helps you. :cool:

[Alex Cavnar, aka alc6379]

Originally posted by hard candy
From a chart in MaximumPC:
1 Athlon XP= 60-90 watts (Make it 75 watts for yours)
2. Motherboard=20-30 watts
3. RAM=20 watts per 256MB=40 watts for yours
4. PCI Card=5-10 watts= does yours have a soundcard?
5. AGP videocard=20-60 watts=20 watts for yours
6. 5400 HD=5-10 watts=10 watts for yours
7. Floppy drive=5 watts= do you have one?
8.CD/DVD drive=10-20 watts=15 watts for yours
9. CPU fan=2-4 watts=3 watts for yours
10. Case fans=2-4 watts= 16 watts (4 watts for the Vantecs, 2 watts for the generics)
Total= 204 watts, very roughly.
The el cheapo PSU's will vary quite a bit in what they put out and if everything is peaking, liike on a boot-up, your wattge could jump over 300 watts in spikes.
I would get a new one, you'll have it when you upgrade in the future.

I appreciate the chart there. I just checked on the specs of my Vantec Fans, and they actually pull 12 watts apiece! :o

Coming from the Musical side of things, I know full well how wattage claims can be misleading. I figured I'd need about 350 watts to be good on that end, so I figured a cheap PSU rated at 500W would suffice.

...Now what I did not take into account was the 3.3v+5v wattage ratings. The power supply, I imagine, totals 3.3+5+12v . That could be pretty misleading...

Since I'm not overclocking this system, I may follow the ocforums recommendation for a good 350W PSU from Antec or Fortron. Just to rule everything out, I'm going to run a quick bit of memtest86 to check out my memory, too. My CPU seems okay, and my cables and cards are all brand new...

[jrbishop79]

as a general rule + or - 10% is standard tolerance for the voltages coming out of your PS; any higher or lower, you should start to worry.....

[Loki3]

Since the guys there over at the oc.forums run their stuff at the very limit I figured if their margins of safety are good enough from them they'd be great for you.