Low +12V line

T

typh00n

Limp Gawd
Joined
Nov 27, 2003
Messages
128
I'm a newb with power supplies but my 12v line is real low. Idle it's like 11.5 but when sisoft's running it can dip to 10.8 :eek:

I know there's a percent error and i monitor with hardware doctor but this shouldn't be that low, right? It a enermax, which i thougth was good, and the 12v line has 17A's, but maybe if i raised the cpu voltage that would help. I thought the cpu runs on the 3.3 or the 5 but why would a cpu arthimetic benchmark lower it that much.

I guess it is getting pretty old and i have 2 HD's, R98 Pro, 2 opticals, and a tornado so maybe it's time to replace? Thanks for any help.

EDIT: oh i forgot, it's a 350W Enermax
 
ATX spec calls for -/+ 5%, so 11.4 to 12.6 would be an acceptable range. 10.8 is way low, but you should verify with a multimeter as software monitoring can often be off.
 
If changing your cpu voltage affects your 12V line significantly then your power supply is crap. Motherboard voltage sensers are not known for their accuracy, so check the actual voltages with a multimeter before doing anything else. 11.5 isn't too bad, but 10.8 sure is.
 
the ATX spec has changed and changed again in order to supply additional +12V
the latest is ATX12V v2.0, so depending on your components and the vintage of that EnerMax, and of course the low rail.....


run the amps needed per rail
http://takaman.jp/D/index.html?english
and compare with your PSUs lable
 
thanks for the link
that's weird though mine is up to spec, the link for my equivalent computer: http://takaman.jp/D/?M=PbQEQbd@jeHjSuTUTpU7UcXAXaZAZavXC0aOP&english

For the 12V it says 16.9 amps and mine's 17. Everything else is way below my power supply, except mine doesn't list 3.3 + 5 + 12V combined Max Watts.
and another thing is it happens with Prime 95, 12V is around 10.7. What does prime stress that uses the 12V? And I had my case open and I could actually hear the tornado speed up as I stopped prime.

I don't have a multimeter but it doesn't make sense to me.
Can I fix this by playing with some voltage?
Thanks again.
 
typh00n said:
. What does prime stress that uses the 12V? .
Click to expand...

these days the CPU

its switched from the +5V to being powered by the +12V
and the latest spec calls for 2 seperate +12V rails

thats close enough to be of concern given the low rail measured in software
grab a multimeter and test it from spinup through to running prime ;)


http://terasan.okiraku-pc.net/dengen/tester/index.html
http://terasan.okiraku-pc.net/dengen/tester2/index.html
http://www.pcguide.com/ref/hdd/op/spin_Power.htm
http://www.pcguide.com/ref/power/sup/output.htm
 
thanks for the info, i'll prolly get a multimeter tomorrow and check it out,
Oh and the first two links are strange, half the page is filled with ?'s .!?
 
japanese

those are multimeter logs of various PSUs from spinup (note the instability in most)
and then under a dynamic load
 
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