Frequently Asked Questions

GENERAL QUESTIONS

Hmonitor was developed especially for Windows NT. Now it works well on all Windows32 based systems: Windows 9x/ME/NT/2000/XP.

Q: Hmonitor doesn't work on my system. All readings are 'XX'. Why?

Hmonitor reads data from some optional h/w chips, called "sensors". Most modern mainboards have these sensors installed. However, if your board have no such chips, Hmonitor is useless for you. There are some chips not supported yet. In addition, some boards have only M/b temp sensors installed whereas others have only CPU temperature sensor.

Q: How can I determine that my board contains any sensor chips?

Usually it clearly mentioned in the M/B manual, and monitored data can be seen on the BIOS screens. There are some known exceptions: Intel AL440LX/SE440BX boards optionally have LM79 sensor installed, but there are no BIOS data screens for it. Also, these boards have option to have sound-card onboard, and such boards have no sensors installed. Often boards with sensors have Intel LDCM software included.

Q: What sensor chips is Hmonitor compatible with?

There are several vendors and models of sensor chips in the market. Hmonitor supports the most often used ones:

Some chips required additional customization of Hmonitor to read data from them. First of all, National LM80 chip should be explicitly selected in Settings window of Hmonitor to work. Look into mainboards list for additional information about particular board.

TEMPERATURE RELATED

First, a lot of boards in the market are capable to measure only one "system" temp. Next, some vendors use non-standard CPU sensor address assignment. You can try to discover valid numbers in Hmonitor settings window. Also, consult mainboards list for additional information about particular board.

HDD TEMPERATURE RELATED

Latest releases of Hmonitor are capable to display HDD drive temperatures from S.M.A.R.T. attributes. This option is enabled by default after installation, and requires monopoly access to the whole drives. This problem is solved in the 4.1.2.3 release.

FANS RELATED

First, You need to have fans with ability to read RPM data - so-called "3-wired" or "smart" fans. On the P-II boards, CPU fan usually has such option. Next, these fans must be plugged into appropriate sockets on the mainboard for receiving this information by sensors chip. Not all sensor chips can monitor all three fans; i.e. Genesys GL518 can read data from only two fans.

Q: I've bought new chassis fan with sense wire, but Hmonitor doesn't show it. Why?

There is some restriction of LM78/79 sensor chips. If you have relatively slow (says, 2500 RPM) fan for chassis, you should plug it into 1st or 2nd sockets only, else you won't see its RPM at all. All you need in this case to do is to interchange wires from CPU fan with this slow fan and change fan captions accordingly.

VOLTAGES RELATED

Unfortunately, not all vendors conform to the specification of sensor chip vendor, or plug voltages in a different order. One such vendor is QDI. Hmonitor has an option for correct voltage readings for some QDI models, consult mainboards list for additional information about particular board. For all other cases, you can simply disable the voltage panel by clicking on the red Hmonitor logo in the upper left corner of the Hmonitor panel, and unchecking "voltages".

Q: What does Vcore2 mean for uni-processor systems?

Vcore2 may be set to monitor variety of voltages such as second CPU core, if any, or 1.5V for Pentium-II GTL BUS, 2.5V for clock generator and so on. This item depends on the application of motherboard vendor. You might need to adjust its nominal value in Hmonitor Settings window.

Q: Voltages seems to be correct, but Vcore and/or VIO voltages are in red. How can I correct that?

Various CPU types and MB models require different nominal voltages. For example, most P-IIs works with 2.0V core, whereas P5 requires 2.8-3.3V. All you need is to go to the settings window, and set right nominal values for Vcore and, possibly, for VIO voltage, because VIO can be varied from 3.3 to 3.6 v for some MB models.

EVENT HANDLING

Hmonitor has several options to inform you about various events and can launch external application if event occurs. For example, if you wish to shutdown your system when CPU fan is occasionally stopped or CPU temp increased higher than red level limit, you can create shutdown.bat containing just one line:

for Windows 95/98/ME:	RUNDLL32.EXE User,ExitWindows
for Windows XP/2003:	shutdown.exe -s -t 0

And specify its name in the Execute field for both CPU fan and CPU temperature lines. Also, you can use any of the shutdown utilities available on the Net for this purpose, i.e. Poweroff, freeware written by Jorgen Bosman. You can download it here.

TEMPERATURE CONTROL (PRO LICENSE NEED)

Under normal circumstances, the CPU isn't always active.  It spends much of its time waiting for the keyboard, hard disk or CD-ROM. What would be more logical than to turn off the CPU for that period? That's exactly what the HLT machine instruction does. Whenever the CPU encounters a HLT instruction, the clock is halted and the CPU enters suspend mode until an interrupt occurs.
Modern operating systems like Linux or Windows NT execute the HLT instruction in an idle priority thread. This thread is always executed when, as the name implies, the CPU is otherwise idle. Therefore no additional execution time is needed, and the CPU will not run slower. This does not hurt performance since the CPU controls the powering-down of specific internal parts by hardware-control, so there's no software intervention needed for explicitly re-enabling a powered-down part. Unfortunately, Windows 95 does not support HLT. To remove this limitation, "Hmonitor" provides an idle thread executing HLT for Windows 95/98.

Q: What is "Thermal Throttle Control"?

Throttling is the ability of the CPU to change between stop (idle), and full speed modes, at very high frequency (hundreds of kilohertz). This CPU switching looks (to the system) as a decrease in the working frequency of CPU, and leads to lower power consumption.
With Hmonitor Pro license, you can use this technology to improve stability of your system. Hmonitor will enable specified throttle level if CPU or system temperature becomes higher than defined threshold, and return system back to full speed when temperature decreased below low threshold. You can specify Temperature bounds and throttling level in Settings window.

Q: What is M/B "Thermal Throttle Control", and how does it differ from CPU "Thermal Throttle Control"?

Both accomplish the same thing: the CPU receives a virtual lower clock frequency, and therefore runs cooler. The difference between the two type of throttle control is simply in the selection of which sensor is used to trigger the throttle condition. In most installations, the M/B should not exceed 45C, and the CPU 60C. Both components will tolerate 70C, but why stress them that much?

Q: Which sensor is the "best" for thermal throttling?

That depends on your specific configuration; your system may have no CPU sensor. For most, setting CPU Throttle Control to 65C will ensure that this expensive component is protected. If your system has multiple sensors, it is still probably best to trigger from the CPU sensor since it's the component which is most easily damaged by heat, and the most expensive to replace.

Q: What is "Full throttle" control?

Selecting a value less than 100% effectively cuts your system CPU clock to the selected percentage less than 100. For example, if you have a PIII/1.0 Ghz system, and you have selected "50%", your CPU would run at a virtual 500 Mhz. Note that this throttling is NOT temperature dependent.

Q: Why would anyone use less than "Full throttle (100%)"?

Users that have overclocked their systems may find that they are unstable under CPU intensive operations. By adjusting the throttle to less than 100% of the clock frequency, system stability maybe enhanced. If you are involved in software development, and want to approximate the performance of a less powerful machine, this feature would also be useful.