12v rail

E

extensive

Geek Trainee
so i just built a new machine a month ago... i had an existing 2 yo PSU that i thought was enough for the job. coolmax 350w modular psu but i just noticed something when running sisoft sandra. it says my 12v rail is around 8.7v! i dont know if this is just a bad reading or if something is really off.

i have been getting some freeze ups. can a computer even run on 8.7v on the 12v rail? it runs and plays games fine for the most part.

are there any other software packages out there that will monitor the psu rails?

setup
amd 5000+ brisbane
xfx 590sli mobo
xfx 8600 gts vid card
2gb ram
1 optical drive
2 sata hard drives raid 0
1 ide hard drive
floppy
 
8.7v is an odd voltage - too low to run any normal 12v devices like HDD's - so can you explain how you get that reading and what are you using to measure it?
(Digital meters are notoriously quirky for the uninitiated.)..a decent £3/$5 analogue meter is a useful piece of kit (buy now, before they stop making 'em).
The term sisoft sandra - I do not understand...are you saying this is "reporting" the voltage - could that be the video card is complaining?
Why isn't the 5v rail down?
I know it's popular to go for ever-larger psu's.
 
i dont have a meter yet... im going to buy one soon. i was just using a software package sisoft sandra SiSoftware Zone it does many benchmarks and monitors your pc.

my bios doesnt have a 12v reading either.
 
So how is it measuring the 12v and why would the 12v rail be so low, yet it remains "happy" with the 5v rail.
A multimeter is quite cheap, get used to it on small items before prodding arround your PC - probably best to monitor at one of the (spare) molex connectors that fit HDD's - but take care...if you're at all unsure get someone else to check it out.
A multimeter is very useful for checking fuses, questionable batteries, bulbs etc - you'll wonder how you managed without one. When not in use an analaogue meter should be switched "off" if it has a position or switched to current witht he leads shorted - this dampens the meter and protects the mechanism against minor shocks, movements etc. Don't pay extra for a digital meter....and analogue is always handy.

I know some bios can set voltages (eg the processor/memory) but I have no experience of them "monitoring" voltages...and in this instance you appear to have something saying it's wildly wrong, yet there is little else to show - I'm even surprised the fans continue to run at such a low voltage - that's why I'm questioning the means of meqasurement, etc.

Over to you
 
just put the positive and negative on the respective positive and negative molex connector? set the meter to 12v dc?
 
extensive said:
just put the positive and negative on the respective positive and negative molex connector?
Click to expand...
yeah, the Molex connector has 4 wires
  • 12V +(red i think)
  • 12V - (black)
  • 5V - (black)
  • 5V + (yellow i think)
the 2 black wires in the middle are - (negative) next to their respective colours (i think)
extensive said:
ac
Click to expand...
:confused: don't you mean DC ?
 
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