Acceptable mobo voltages?.
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From: Tom McCreadie on 22 Jul 2010 17:59 Perhaps off topic for this NG: Below is a report by the utility 'PC Wizard' of the motherboard voltages for my Asus desktop PC (P4C800-E del / Antec TruePower480 PS) and my core 2 Duo laptop (Toshiba Satellite A110-323). This was measured with no major apps running. The desktop PC was loaded with 2 internal HD's, a Matrox P650 video card and 4 PCI cards. The Asus desktop data seem solid enough but the low laptop values surprised me. (Switching from mains to battery operation made no change). Should I be concerned about those low laptop voltages? It works fine. though I don't have any earlier measurement history to reveal any possible trend Or are such voltages par for the course for laptops in general, and within tolerances anyway? Thanks for any insight, Tom Toshiba Asus P4C800-E del/ TruePower480 Voltage CPU 2.05 V 1.41 V +3.3 Voltage 2.05 V 3.09 V +5 Voltage 3.44 V 4.81 V +12V Voltage 8.19 V 11.86 V Battery #0 11.10 V n/a
From: Paul on 22 Jul 2010 21:40 Tom McCreadie wrote: > Perhaps off topic for this NG: Below is a report by the utility 'PC Wizard' of > the motherboard voltages for my Asus desktop PC (P4C800-E del / Antec > TruePower480 PS) and my core 2 Duo laptop (Toshiba Satellite A110-323). This was > measured with no major apps running. The desktop PC was loaded with 2 internal > HD's, a Matrox P650 video card and 4 PCI cards. > > The Asus desktop data seem solid enough but the low laptop values surprised me. > (Switching from mains to battery operation made no change). Should I be > concerned about those low laptop voltages? It works fine. though I don't have > any earlier measurement history to reveal any possible trend Or are such > voltages par for the course for laptops in general, and within tolerances > anyway? > > Thanks for any insight, > Tom > > Toshiba Asus P4C800-E del/ TruePower480 > Voltage CPU 2.05 V 1.41 V > +3.3 Voltage 2.05 V 3.09 V > +5 Voltage 3.44 V 4.81 V > +12V Voltage 8.19 V 11.86 V > > Battery #0 11.10 V n/a Those measurements are made by the hardware monitor interface on the SuperI/O chip. There are a number of identical measurement channels. The channels have a certain full scale value, such as 4.096 volts measured in 256 steps (8 bit ADC). By applying smoothing or averaging functions to the stream of readout values, you end up with values that are not a multiple of 0.016 volts. Voltages higher than the full scale value, must be run through a voltage divider, so that they fit within the measurement range. The resistors used for that, tend to degrade the accuracy of the measured result (to a point worse than a cheap multimeter). Take the 12V rail as an example. If a voltage divider is set up, to take 1/4 of the measurement lead, then a measured value of 3V on that channel, would correspond to 12V. Somehow, the software needs to find out, that it needs to multiply the measured value by 4 to get the right answer. The extra "headroom" in my example, allows the hardware monitor to read a badly out of spec 15V value, and stay within the dynamic range of the 4.096V ADC conversion (15/4 volts applied to the converter input). If we take all your Toshiba values, they appear to be about 2/3rds of the correct value. It looks like some scaling math isn't working right. As a double check, you might want to look up what CPU your Toshiba uses, to see what measured value for VCore would make sense. On your P4C800-E, it's hard to say what is happening there. My recollection is, some of the Antec Truepower supplies, have feedback wires on all three major rails, so the Truepower should be able to better regulate to the correct value. (If your Truepower was "sick", I suppose anything is possible.) Any time you have doubts, a multimeter set to the volts range, can be used to verify some of the power supply voltages. Knowing where to probe, to get the CPU voltage, is a bit more difficult. (The best place to measure, is likely two pins on the CPU designed for this purpose. The pins monitor the supply voltage as seen by the CPU silicon die itself, for the most accurate result. Those pins may be what is connected to the hardware monitor, to give the 1.41V reading.) An early P4 would have been in the 1.5V range or so, so the value shown isn't alarmingly different. For the Toshiba battery voltage, you can try taking 11.1 and multiplying it by the suspected missing scale factor of 1.5 . That gives 16.65 volts. You can compare that to the nominal value printed on the battery pack. My experience, of checking a few different motherboards, usually shows one rail measurement is out to lunch, which probably means the scaling math in the program displaying the results, is just wrong. Checking with my multimeter, shows the power supply values to be pretty close to the correct values, and the multimeter measurements usually make the power supply look heroic, while the hardware monitor readings usually make the power supply look like a slouch (out of spec). On occasion, someone will report they're getting a 0.0 reading on a major rail, and you just know that can't be right :-) The computer would be "black screen", if it was really zero. Paul
From: Tom McCreadie on 23 Jul 2010 05:53 Paul <nospam(a)needed.com> wrote: >Tom McCreadie wrote: >> Perhaps off topic for this NG: Below is a report by the utility 'PC Wizard' of >> the motherboard voltages for my Asus desktop PC (P4C800-E del / Antec >> TruePower480 PS) and my core 2 Duo laptop (Toshiba Satellite A110-323). This was >> measured with no major apps running. The desktop PC was loaded with 2 internal >> HD's, a Matrox P650 video card and 4 PCI cards. >> >> The Asus desktop data seem solid enough but the low laptop values surprised me. >> (Switching from mains to battery operation made no change). Should I be >> concerned about those low laptop voltages? It works fine. though I don't have >> any earlier measurement history to reveal any possible trend Or are such >> voltages par for the course for laptops in general, and within tolerances >> anyway? >> >> Thanks for any insight, >> Tom >> >> Toshiba Asus P4C800-E del/ TruePower480 >> Voltage CPU 2.05 V 1.41 V >> +3.3 Voltage 2.05 V 3.09 V >> +5 Voltage 3.44 V 4.81 V >> +12V Voltage 8.19 V 11.86 V >> >> Battery #0 11.10 V n/a > >Those measurements are made by the hardware monitor interface on >the SuperI/O chip. > >There are a number of identical measurement channels. The channels >have a certain full scale value, such as 4.096 volts measured in >256 steps (8 bit ADC). By applying smoothing or averaging >functions to the stream of readout values, you end up with >values that are not a multiple of 0.016 volts. > >Voltages higher than the full scale value, must be run through a >voltage divider, so that they fit within the measurement range. >The resistors used for that, tend to degrade the accuracy of >the measured result (to a point worse than a cheap multimeter). > >Take the 12V rail as an example. If a voltage divider is set up, >to take 1/4 of the measurement lead, then a measured value of 3V >on that channel, would correspond to 12V. Somehow, the software >needs to find out, that it needs to multiply the measured value by 4 >to get the right answer. The extra "headroom" in my example, allows >the hardware monitor to read a badly out of spec 15V value, and >stay within the dynamic range of the 4.096V ADC conversion (15/4 >volts applied to the converter input). > >If we take all your Toshiba values, they appear to be about 2/3rds >of the correct value. It looks like some scaling math isn't working >right. > >As a double check, you might want to look up what CPU your Toshiba >uses, to see what measured value for VCore would make sense. > >On your P4C800-E, it's hard to say what is happening there. My >recollection is, some of the Antec Truepower supplies, have >feedback wires on all three major rails, so the Truepower should >be able to better regulate to the correct value. (If your >Truepower was "sick", I suppose anything is possible.) > >Any time you have doubts, a multimeter set to the volts range, >can be used to verify some of the power supply voltages. Knowing >where to probe, to get the CPU voltage, is a bit more difficult. >(The best place to measure, is likely two pins on the CPU designed >for this purpose. The pins monitor the supply voltage as seen >by the CPU silicon die itself, for the most accurate result. Those >pins may be what is connected to the hardware monitor, to give the 1.41V >reading.) > >An early P4 would have been in the 1.5V range or so, so the >value shown isn't alarmingly different. > >For the Toshiba battery voltage, you can try taking 11.1 and multiplying >it by the suspected missing scale factor of 1.5 . That gives 16.65 volts. >You can compare that to the nominal value printed on the battery pack. > >My experience, of checking a few different motherboards, usually >shows one rail measurement is out to lunch, which probably means >the scaling math in the program displaying the results, is just wrong. >Checking with my multimeter, shows the power supply values to >be pretty close to the correct values, and the multimeter measurements >usually make the power supply look heroic, while the hardware monitor >readings usually make the power supply look like a slouch (out of >spec). > >On occasion, someone will report they're getting a 0.0 reading >on a major rail, and you just know that can't be right :-) The >computer would be "black screen", if it was really zero. > Thanks, Paul. for the considered and informative reply. Very thorough...some German chromosomes back in your ancestral line? <g> Further info, FWIW: Asus: - 3.2 GHz P4 Prescott. - 'Hardware Monitoring', reported by PC Wizard, was Winbond W83627THF Toshiba: - Intel i945GM/GME chipset with 1.66 GHz Core 2 Duo Mobile T5500 - 'Hardware Monitoring' National LM79. - AC adaptor PA-1650-02 output 19V / 3.32A - rechargeable battrey options listed in the manual for their Satellite model range: - 4-cell Li ion pack , 14.4V / 2000mAh - 6-cell Li ion pack , 10.8V / 4000mAh <= I had this one (model no PA3465U-1BRS) - 8-cell Li ion pack , 14.4V / 4300mAh So maybe my laptop voltage values are being scaled by the factor 10.8/14.4 ? Anyway, both machines seem to be working OK, so I'll probably just let sleeping dogs lie for now <g> Tom -- Tom McCreadie Live at The London Palindrome - ABBA
From: larry moe 'n curly on 23 Jul 2010 17:34 Tom McCreadie wrote: > Below is a report by the utility 'PC Wizard' of > the motherboard voltages for my Asus desktop PC (P4C800-E del / Antec > TruePower480 PS) and my core 2 Duo laptop (Toshiba Satellite A110-323). This was > measured with no major apps running. The desktop PC was loaded with 2 internal > HD's, a Matrox P650 video card and 4 PCI cards. > Toshiba Asus P4C800-E del/ TruePower480 > Voltage CPU 2.05 V 1.41 V > +3.3 Voltage 2.05 V 3.09 V > +5 Voltage 3.44 V 4.81 V > +12V Voltage 8.19 V 11.86 V > > Battery #0 11.10 V n/a Rule of thumb: really wierd voltage readings have to be wrong because if they were accurate, the computer wouldn't be able to run well enough to do anything, including run PC Wizard. Hard drives need +5V within about 5-10% of that value, and desktop HDs also need +12V within the same tolerance.
From: Paul on 23 Jul 2010 17:57
larry moe 'n curly wrote: > Tom McCreadie wrote: >> Below is a report by the utility 'PC Wizard' of >> the motherboard voltages for my Asus desktop PC (P4C800-E del / Antec >> TruePower480 PS) and my core 2 Duo laptop (Toshiba Satellite A110-323). This was >> measured with no major apps running. The desktop PC was loaded with 2 internal >> HD's, a Matrox P650 video card and 4 PCI cards. > >> Toshiba Asus P4C800-E del/ TruePower480 >> Voltage CPU 2.05 V 1.41 V >> +3.3 Voltage 2.05 V 3.09 V >> +5 Voltage 3.44 V 4.81 V >> +12V Voltage 8.19 V 11.86 V >> >> Battery #0 11.10 V n/a > > Rule of thumb: really wierd voltage readings have to be wrong because > if they were accurate, the computer wouldn't be able to run well > enough to do anything, including run PC Wizard. Hard drives need +5V > within about 5-10% of that value, and desktop HDs also need +12V > within the same tolerance. In some cases, you can get different values displayed on the computer, by using Asus Probe, MBM5 (for older computers), Speedfan from almico.com and so on. So an alternative to grabbing the multimeter, is to try some other programs to do the readout. It's possible even a Linux LiveCD, will have some utilities available for reading the hardware monitor. Some other utility may give better values. And I agree with the observation about hard drives. They're picky about both the 5V and 12V, and slightly low values cause a desktop hard drive to "spin down and spin up". I've seen that happen here, when I had too much load on one of my Molex cables. It doesn't take much to upset the drive. Paul |