Page 1 of 1

Double forward in 5V based machine

PostPosted: February 22nd, 2015, 12:09 pm
by Pentium
So I have a ClearOS router in my room, which is run on an old machine.
Specs:
Intel D815EEA
Pentium III 933MHz Coppermine
3x 128MB PC133
GeForce MX440 32MB
Two DVD drives
Seagate Barracuda ATA IV 40GB (With 81,800 POH!)
80mm intake fan
Pixxo (Zumax/Topower) realistically 350W PSU. The PSU is double forward, with most of its power on the 12V, and it has two rails with a 20A schottky each. The 5V and 3.3V both have a 30A schottky. I figured this shouldn't be a problem, maybe it just doesn't like the dual 12V rail system?


The thing idles almost all the time, even when pumping 7mB/s from the internet through it. The 5V sits at 5.04V, and the 12V (molex) idles at 12.28V. Occasionally the CPU will spike for a few seconds to 20% usage, and at this time the 5V will drop to 4.96V and the 12V will go up to12.49V. Does this indicate that it really doesn't like this system? It's annoying because when this happens I will hear the fans rev up and then down again.

Oh you know what.....I just checked the 3.3V while typing out this post and it's 3.50V Time to find a half bridge. Is there any reason why some PSU's just hate crossloading so much?

Re: Double forward in 5V based machine

PostPosted: February 22nd, 2015, 8:05 pm
by LongRunner
A bit off-topic, but…

Pentium wrote:Seagate Barracuda ATA IV 40GB (With 81,800 POH!)

Based on extrapolating the SMART reports from my own Seagates, it appears that the normalised value associated with that counter will reach the lower limit of 1 (it starts at 100) after about a decade of continuous use (87,660 hours). As the threshold is set at 0, the attribute will never actually "fail". I assume the normalised value on your drive is around 7?

As for the PSU, I might suggest recapping a Macron MPT-xxx, or something somewhat similar.

Re: Double forward in 5V based machine

PostPosted: June 26th, 2017, 3:21 am
by LongRunner
Well, look what I came across: A document by Seagate themselves confirming my guess. :cool:

http://t1.daumcdn.net/brunch/service/us ... EEQEbU.pdf

So, Pentium: Are you there yet?