MBProbe
Frequently Asked Questions
Copyright 1998-2001 Jonathan Soon Yew Teh
http://web.bham.ac.uk/jst829/mbprobe/
General
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Q: Does MBProbe slow down my computer?
A: Yes, by a little. ANY program running in the background will slow down the
computer. The question is: by how much? MBProbe only polls the monitoring
chips once every 5 seconds and does some trivial calculations and
comparisons so the impact on system performance is negligible. You
certainly won't notice it and it probably won't affect benchmarks like
Winbench or Winstone either.
Q: It says "Unable to open giveio.sys driver" in Windows NT/2000 and quits.
I thought you said it supported Windows NT/2000.
A: It does. You must install the giveio.sys driver first using NTINST
otherwise MBProbe will be unable to access I/O ports. Refer to readme.txt.
Q: Why does it detect my CPU incorrectly?
A: Many CPUs share the same CPUID (see techinfo.txt) and MBProbe does not
make any attempt to differentiate them as this is not its primary purpose.
Get a proper CPU identification program instead.
Q: Why does my system hang/reboot when MBProbe tries to suspend it?
A: This is a power management issue rather than an MBProbe issue as it is
calling a proper, documented Win32 API function to suspend the system.
Your system doesn't have power management setup properly or one of the
drivers in your system does not support power management correctly and
needs to be upgraded.
You can opt for MBProbe to do nothing or to shutdown the system instead.
Q: How do I change the directory where the logs are generated?
A: Simply start MBProbe from a different directory. Edit the properties of
the MBProbe shortcut and change the path in the 'Start in' entry.
Q: Why does Scandisk or Defrag keep restarting?
A: The logging options write something to the hard drive occassionally,
especially history logging. Disable logging for the duration of the
Scandisk or Defrag.
Q: How do I specify arguments for the executable run by a warning event?
A: You can't. Write a script for this using a DOS batch file, JScript or
VBScript. You will require the Windows Scripting Host for the latter two.
Other scripting languages like Perl will also work as long as you
associate the extension (e.g. .perl) with the correct interpreter (e.g.
c:\perl\bin\perl.exe). In fact, any file type with an 'Open' function
defined will work.
Q: How do get it to do ... when a warning event occurs?
A: Write a script to do it and put that as an executable. With the right
scripting language (and some programming skills) you can get it to do
practically anything :)
Q: I've recently upgraded from a rather old version of MBProbe and/or
changed my motherboard and now MBProbe is behaving strangely?
A: Quit MBProbe and delete the registry key:
HKEY_LOCAL_MACHINE/Software/Jonathan Teh/MBProbe
Restart MBProbe and it will restore its default settings.
Hardware
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Q: How do I know whether my motherboard has a monitoring chip?
A: The easiest way is to just run MBProbe and see if it finds anything. Some
recent motherboards do include a hardware monitoring chip.
The following indicates your motherboard has a monitoring chip:
1. The BIOS setup has voltage/temperature/fan speed readings.
2. The motherboard comes bundled with some monitoring software or Intel
LANDesk Client Manager with temperature monitoring.
3. You check the motherboard and find one on it :)
These may indicate that your motherboard does not have a monitoring chip:
1. You have a branded computer (e.g. Dell, Gateway, HP) or have an OEM
motherboard. Some motherboard manufacturers like Asus, Intel and QDI
do not include hardware monitoring in their OEM boards.
Q: I'm very sure my motherboard has a hardware monitoring chip but it still
says "None".
A: So it does. Check the list of unsupported chips first to see if the chip
in your motherboard is listed there. If it is, you're out of luck.
If not, it may be that your chip isn't where MBProbe expects it to be.
The LM78-type chips are searched for at ISA port 290h. Other hardware
monitoring chips are searched for at SMBus address 28h-2fh. Chips at other
ports/addresses will not be found. If you have such a configuration, try
to find out the address of the chip and contact me with the information.
SMBus monitoring chips are slave devices and as such need a supported
SMBus host.
Q: Does MBProbe support multiprocessor systems?
A: Yes, it will work fine on systems with more than 1 CPU. However, in order
to monitor more than one CPU, it would require that the monitoring chips
support monitoring more than one CPU. E.g. the Asus P2B-D uses a W83781D
which can monitor 2 CPU core voltages, 2 CPU core temperatures (via
thermistors) and 2 CPU fans. Check the with the motherboard manual or
manufacturer.
Q: My SMBus host shows "(Disabled)". How do I enable it?
A: Some chipsets (e.g. ALi) have the SMBus host and power management
controller as one device. Try enabling power management in the BIOS setup.
For other chipsets, a BIOS upgrade may be necessary. Contact your vendor.
Q: My motherboard has a VIA MVP3 chipset. Why isn't the SMBus being detected?
A: Most MVP3 chipsets actually have a VT82C586B south bridge which has an I2C
host and not an SMBus host. This is unsupported (read the manual for the
reason). If someone would care to donate an MVP3-based motherboard to me
then this could change.
Q: What's SMBus?
A: SMBus is Intel's System Management bus which is subset of the Philips
I2C bus. It is a two-wire serial interface for devices such as hardware
monitors, smart batteries and power management related chips. Devices on
the bus are SMBus slaves and thus requires an SMBus host to communicate
with them. For further information refer to techinfo.txt for the
location of the SMBus specification sheet.
Voltage
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Q: The voltage readings are screwed. What's wrong?
A: This is due to some motherboard manufacturers connecting different
voltages to the monitoring chips. Refer to the known issues section in the
readme. Please report your complete set of readings (from MBProbe and
another source such as the BIOS, in the original order), motherboard model
and I will try and correct it. For the time being, disable the warnings.
There is an option to use an alternate voltage order for SiS5595 chips.
Try it and see if it corrects the readings.
Q: What do all the voltages mean?
A: Vccp1/2 : CPU core voltages for 1st and 2nd CPU
1.5V : Vtt or the AGTL+ bus termination voltage
2.5V : Good question ;-)
3.3V : I/O voltage (communications between chips)
5V, 12V : Used for motors (e.g. drives) and fans
-5V, -12V: Some op-amps need negative voltages
Vsb : Standby voltage (ATX motherboards)
Vbat : Battery voltage (not sure what this means for desktop PCs)
Q: What is Vccp2 (and sometimes +2.5V) supposed to be?
A: Any number of things. If the monitoring chip supports this reading then
MBProbe simply reports it. Only the motherboard manufacturer knows what it
could be. It could read:
o Similar to Vccp1
Dual processor boards have one reading for each processor.
One exception is the Abit BP6 where 'Vccp2' is a 1.5V (Vtt) reading
and the real Vccp2 is the Vbat reading.
o Same as Vccp1
On my (uniprocessor) Asus P2B, they're both the same.
o 3.3V
The Intel VC820 seems to have Vccp2 connected to 3.3V.
o 2.5V
That's what the +2.5V reading is supposed to be.
o 1.5V
Some boards (Intel, QDI) have Vccp2 or +2.5V connected to Vtt instead
which has a nominal voltage of +1.5V. Adjust the nominal voltage in the
voltage tab accordingly. Vtt is the AGTL+ bus termination voltage.
o Some weird value
The Tekram P6B40-A4X connects the Vccp2 input to a thermistor instead
and as such gives a nonsensical Vccp2 reading. Disable the warning for
it and select "Tekram" for the CPU temperature.
Q: Why are some of the voltage readings/adjustments disabled?
A: Some monitoring chips do not support certain readings. E.g. LM78-type
chips are normally not setup to monitor +2.5V.
Q: Why are the +12V, -5V and -12V readings slightly off?
A: Please switch the voltage divider mode in the properties dialog.
Reason: Voltages are 'divided' with resistors before connection to the
chip. Most motherboard manufacturers actually use resistor values meant
for the Winbond W83781D even though they have installed an LM78/79. Some
motherboard manufacturers do use the proper resistor values (e.g. Tekram)
hence the need for the new switch as there is no way of determining the
values via software. The default is the Winbond values; if these give
readings which are too low, switch to the LM78 values.
Q: Why do I get weird voltage readings on a Myson MTP008?
A: This chip uses the same register for temperature 3 and -12V as well as
temperature 2 and +12V. Hence only one or the other will make sense.
Q: Why can't I enable warnings for both Vccp2 and -12V?
A: You have a Heceta 2/3 monitoring chip. The Vccp2 and -12V readings are
read from the same location hence only one of the readings would make
sense. This depends on what the motherboard manufacturer actually
connected to that input. Intel boards have it connected it to -12V.
Q: The monitoring software that came with my GL518SM shows 4 voltages but
only the Vccp1 reading in MBProbe is correct.
A: The GL518SM can monitor 4 voltages but can only show the value for 1, in
this case it's Vin3 on chip which generally is connected as Vccp1. The
other voltages can only be monitored for exceeding the limits but their
current values cannot be read. The monitoring software you have is
'reading' the value by continuously resetting the limits and checking
whether the voltage exceeds that limit. This is not implemented in
MBProbe and probably will never be.
Q: It displays my CPU voltage as 0.00V. What's wrong?
A: Chances are your CPU is either too old or too new. In particular, CPU
voltages for 486 and early Pentium 60/66 CPUs are not in the program since
it is assumed that motherboards supporting CPUs that old would not be
equipped with a hardware monitoring chip.
The other case is that the CPU is too new and MBProbe has not been updated
yet to take this into account. Please e-mail me with full details of your
processor (manufacturer, model, clock, voltage) and I will update MBProbe.
Q: It detects my CPU voltage incorrectly. What effect does this have?
A: This is harmless; simply select the correct CPU core voltage in the
'Voltage' tab.
MBProbe guesses the CPU voltage via its CPUID. This is basically the
information you see under 'CPU information' on the 'General' tab in
Properties. The problem with this is that the CPUID doesn't always
differentiate every single variant of a particular CPU.
You can either guess the voltage of your CPU based on the value returned
by the monitoring chip, check the table in techinfo.txt or look for it
on the CPU itself.
Temperature
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Q: What's the ideal temperature for my system?
A: Good question. For motherboards, the default warning of 40°C seems
reasonable as most boards seem to hover around 25-35°C. Intel recommend
that the temperature of the air surrounding the CPU (i.e. "motherboard
temperature") be no higher than 40°C. The temperature of the interior of
the case is generally around 10°C higher than room temperature so adjust
accordingly. Notebook motherboard temperatures are higher and are usually
in the range 60-70°C.
For CPUs, it depends on the type of CPU and how the temperature is measured.
If the sensor is located beneath the socket (usually Socket 7) then you need
to adjust a temperature offset first (see techinfo.txt).
A thermistor pasted to the heatsink of a CPU should be reading CPU 'case
temperature'. Intel recommend a maximum case temperature of 70-75°C
depending on the exact model. Check http://developer.intel.com. for more
info. Most people seem to get a reading of 30-45°C.
Newer sensor chips which measure the temperature of the silicon die via a
thermal diode on the CPU itself would read the 'die temperature' and this
would be higher. A 'normal reading' would be in the range of 55-80°C (as
seen on a Toshiba Tecra 8000 notebook).
I've also measured temperatures of graphics chips using a thermistor
attached to the heatsink. For reference, I get 40-48°C on an ATI Rage 128
and 47-55°C on a 3dfx Voodoo Banshee, Matrox G400MAX and Nvidia Riva TNT
with the manufacturer's heat sink and fan (if equipped).
Q: Can my board monitor CPU temperature?
A: I don't know. If MBProbe assigns a sensor to the CPU temperature, then it
probably can. You may have to change some settings and/or plug in a
thermistor into the motherboard and attach it to the CPU. Note that most
LM78/79 and Heceta2 equipped boards cannot monitor CPU temperature. Refer
to techinfo.txt for board-specific details.
Q: Which one is my CPU temperature?
A: The default sensor chosen by MBProbe works only some of the time. Refer to
techinfo.txt for the correct sensor to choose.
Some motherboards have their own specific sensor types- choose those
instead. E.g. the Asus CUSL2 uses a different calculation for the CPU
temperature.
The Tekram P6B40-A4X uses the Vccp2 input for a thermistor instead and
this is sensor 'Tekram' under MBProbe. Of course, on other boards this
will give you a nonsensical value as Vccp2 is usually connected to the
CPU core voltage or to Vtt (1.5V). Do NOT try to reconnect it to a
thermistor in a vain attempt to get a temperature reading!
Q: What's the Aux1,2 reading measuring?
A: It depends on the motherboard. Some motherboards provide a 2-pin header to
connect an external thermistor to measure whatever you wish. If left
unconnected, it could show weird readings like -48°C or 125°C. Disable the
warning in that case.
If no 2-pin header is provided and it shows a sensible reading, then it is
probably an extra motherboard temperature reading.
Q: How accurate are the temperature readings?
A: Most of the sensor chips are rated for +/-3°C when measuring on-chip
temperature and +/-5°C when measuring remote diode temperature. Some
exceptions are listed below:
ADM1020/1/1A/2: +/-1°C on-chip, +/-3°C remote diode
ADM1023 : +/-1°C on-chip, +/-1°C remote diode
LM82/3/7 : +/-3°C on-chip, +/-4°C remote diode
LM84 : +/-1°C on-chip, +/-5°C remote diode
Q: What type of thermistor should I use?
A: If you have a Winbond chip it's an NTC type, 10Kohm @ 25°C, B-value 3435.
Visit your local electronics hobbyist store for the thermistors or ask
the dealer where you purchased your motherboard from. Asus sells the P2T
thermistor for their boards.
Q: Why do the temperature readings show -48°C?
A: You probably have a Winbond chip. The two -48°C readings are coming from
external temperature inputs which are unconnected. You need to get two
thermistors and connect them to the corresponding pins on the motherboard.
On my Asus P2B, they are labeled JTCPU and JTPWR.
Q: Why do I get the same readings from the LM75|1, 0 and W8378xx:2, 3?
A: The Winbond chips simulate two LM75s (W83783S simulates 1 only) and as
such gives identical readings to its own 2nd and 3rd temperature inputs.
Usually W8378xx:2 is equivalent to LM75:1 and W8378xx:3 to LM75:0.
Q: Why is the 'CPU thermal diode' section greyed out?
A: They are only enabled for certain chips. Winbond W83782D and W83783S chips
accept either a thermal diode or thermistor on their temperature inputs.
Enable the appropriate box to ensure a correct reading of the CPU
temperature. Abit boards have the thermal diode connected to Sensor:2.
Q: When is a CPU temperature offset needed?
A: This is normally needed on motherboards using a temperature sensor under
a socketed CPU. The sensor is not in direct contact with the CPU, hence
the requirement for an offset to account for the insulating layer of air
between the sensor and the CPU.
This usually applies only to Socket 7 boards.
Q: Why is the default temperature display in Fahrenheit?
A: It is the default only if your regional settings (in the Control Panel) is
set to English (United States). Many people forget to change the regional
settings when installing Windows. Just change the temperature display to
Celsius if you like.
Fans
----
Q: Why are some of the fan readings/settings disabled?
A: Some monitoring chips do not support 3 fan inputs. Refer to the feature
table in techinfo.txt. Also, some chips have 3 fan inputs but the divisor
on the 3rd input is fixed at 2.
Q: Why are my fan readings displayed in the wrong place?
A: Some motherboard manufacturers (Abit, Intel) have the CPU fan connected to
the 3rd fan input. Just change the Fan 3 label to 'CPU'. Others seem to
use Fan 1 as the CPU fan reading.
Q: Why does it show 0RPM even though I have a fan plugged in?
A: You need a fan with tachometer output. Such fans usually have 3 wires for
+Vcc, ground and tachometer output. If you have such a fan plugged in and
it still shows 0RPM you may have to adjust the fan divisor.
Q: What are fan divisors for?
A: The monitoring chips do not directly return the RPM of the fan directly;
instead they return the number of 'counts'.
As a guide, use the following divisor values corresponding to your fan's
nominal RPM:
Divisor Nominal fan RPM RPM Range Resolution (at nominal)
1 8800 5294-1350000 ~58
2 4400 2647- 675000 ~29
4 2200 1324- 337500 ~14
8 1100 662- 168750 ~ 7
If you have a fan connected and the reading shows 0RPM, try selecting a
higher divisor. Always use the lowest possible divisor that still gives a
non-zero reading to ensure sufficient resolution (jumps between RPM
indications).
In practice, MBProbe has a maximum fan reading of 9999RPM.
Q: Why don't the fan divisor changes take place immediately?
A: Fan divisors have to be set on the hardware monitoring chip and it only
takes effect the next time a reading is taken, hence the delay.
Download Driver Pack
After your driver has been downloaded, follow these simple steps to install it.
Expand the archive file (if the download file is in zip or rar format).
If the expanded file has an .exe extension, double click it and follow the installation instructions.
Otherwise, open Device Manager by right-clicking the Start menu and selecting Device Manager.
Find the device and model you want to update in the device list.
Double-click on it to open the Properties dialog box.
From the Properties dialog box, select the Driver tab.
Click the Update Driver button, then follow the instructions.
Very important: You must reboot your system to ensure that any driver updates have taken effect.
For more help, visit our Driver Support section for step-by-step videos on how to install drivers for every file type.