Phil Weldon wrote:
'don't look' wrote:
| Sorry,.By "jumping"I meant every couple to several seconds the value
| switches from 11.64 to 11.71. I've never seen it higher than 11.71
| or
lower
| than 11.64.
| how do I tell the Voltage while running a program?Is there a utilty
| that will log it?
_____

The EXTREMELY small voltages changes are completely meaningless for a
12 VDC output. The voltage is only changing over a range of 0.07
volts. The analog to digital conversion used by the monitoring chip
probably makes that small a change just an LSB error (like rounding)
and it may not be able to give an accurate reading in the hundredth's
place.

From a data acquisition standpoint, think about the analog to digital
conversion. These things can't be 100% accurate. If the voltage took an
analog waveform, it would be 100% continuous, meaning infinite differences
between readings. So it would say 11.644293865 one second then
11.641232398235 to infinity digits (theoretically). Since we're dealing
with digital systems, the data acquisition bit of the computer has to
separate the readings in terms of time and levels. We'll deal with the
levels first. Let's say that the voltage sensor is a +20V sensor with 8-bit
resolution. 8 bits means you have 2^8 levels, or a total of 256 different
levels to state what a typical analog reading would "fit" in. The computer
can't see any more detail than that.

20V/256 different levels=.078V which means that if your voltage is hovering
around 11.64, it would have a whole .078 of "play" before the signal
integration system would be able to assign it to a different number. The
computer would be assigning anything in the range of 11.60V to 11.67V the
value "11.64V" because it's the computer's best guess at what the voltage
is, since it can't see more resolution. Correspondingly, if it exceeds
11.67V and fits in the range of 11.67V to 11.75V then it will assign the
value "11.71V."

If it's hard to see, open up Speedfan and watch your temperatures over time.
You'll notice that you won't see tenths of a degree... you'll see half a
degree resolution at most, but what happens in between those hills and
valleys? You can use your eyes to visually integrate the signal over time,
or if you're really anal, import it into Excel and do some curve fitting to
figure it out.

As you can see, your 12V rail might be moving around up to .13V, but that's
well within the spec. You're good.
--
Phil

There are small applicatons that can monitor and log voltages,
temperature, and fan speeds. Most can display values in the
'toolbar'. For that to happen, your particular motherboard must
implement the necessary circuitry and you must find a monitoring
application that is compatible with your motherboard. MotherBoard
Monitor used to be the favorite, but it has not been updated and
several years and no longer works on new motherboards with new
monitoring chips. CPUCool and SpeedFan are two possibilities.

Phil Weldon

"don't look" don't wrote in message
...
|
| "Phil Weldon" wrote in message
| link.net...
| 'don't look' wrote:
| | According to my motherboards' software overclocking
| | utilty(Superstep)
| the
| | 12V line doesn't look good.All the others(3,3v,5v) etc. are
stable.This
| is
| | at idle.
| | Mobo is Winfast NF4UKAA-8EKRS w/2gb ddr.Power supply is Ultra
| | X-finity
| 500W
| | SLI.Video card is Nvidia 7900GS.
| | I have 24 pin to motherboard plus 4-pin to cpu plus 6 pin to
| | video. Is this normal fluctuation?
| _____
|
| The ATX12V rev 2.2 power supply specifications call for +/- 5%
regulation
| on
| the 12 VDC lines; anything within 11.40 VDC to 12.60 VDC is OK.
| See
|
http://www.formfactors.org/developer...public_br2.pdf
| .
|
| 'Jumping' is not much of a description, and you haven't given any
| information about voltage behaviors when the system is NOT at
| idle.
|
| Always put ALL the information for a post in the body; don't place
| important
| bits just in the subject line.
|
| Phil Weldon
|
|
|
http://www.formfactors.org/developer...public_br2.pdf
| "don't look" don't wrote in message
| ...
| | According to my motherboards' software overclocking
| | utilty(Superstep)
| the
| | 12V line doesn't look good.All the others(3,3v,5v) etc. are
stable.This
| is
| | at idle.
| | Mobo is Winfast NF4UKAA-8EKRS w/2gb ddr.Power supply is Ultra
| | X-finity
| 500W
| | SLI.Video card is Nvidia 7900GS.
| | I have 24 pin to motherboard plus 4-pin to cpu plus 6 pin to
| | video. Is this normal fluctuation?
| |
| |
|
|
| Sorry,.By "jumping"I meant every couple to several seconds the value
| switches from 11.64 to 11.71. I've never seen it higher than 11.71
| or
lower
| than 11.64.
| how do I tell the Voltage while running a program?Is there a utilty
| that will log it?