Hardware Monitor

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Hardware Monitor

Known Issues

There are currently no known issues for this product.

Release Notes

Computers with a graphics chip of the ATI RADEON X2000 series using Mac OS X 10.5.2 with Leopard Graphics Update 1.0 are not capable of rendering the output feature "Screen Display" correctly: Mac systems which use a graphics processor of the RADEON X2000 series made by AMD/ATI show significant problems when activating the option "Show Screen Display" in the application. A rectangular area with graphical errors appears behind the screen display output. The 10.5.2 graphics drivers for the X2000 series are not mature enough to display this feature correctly.

Workaround: Update to Mac OS X 10.5.3 to fix this problem.

When using Mac OS X Leopard with a computer containing an NVIDIA GeForce graphics chip, the whole screen output may unexpectantly stop responding ("freeze") when using certain graphics features of the application: Mac systems which use Mac OS X 10.5.x and a graphics processor of the NVIDIA GeForce series may fail during normal operation because the Leopard drivers are not yet working correctly. The driver is losing the connection to the graphics processor and does not recover.

Workaround: Restart the computer and open the Console application. Check if either the message "NVChannel(GL): Graphics channel exception!" or "NVChannel(GL): Graphics channel timeout!" have been recorded by Mac OS X in the system log for the time when the screen stopped responding. If yes, contact Apple stating the problem and suggest that the graphics card or its drivers have to be replaced.

After waking from sleep mode, the Main Logic Board Air Inlet sensor of some Power Macintosh G5 Dual Core systems shows negative or no readings: When a dual core PowerMac G5 wakes from sleep mode, the temperature reading of the air inlet sensor may show incorrect values.

Workaround: This is a known defect in specific versions of Mac OS X Tiger. This particular sensor is not correctly woken up by the operating system. We have made Apple aware of this problem and hope they will resolve it in future versions of Mac OS X. In the meantime, you can restart the computer to reset the sensor hardware, or disable data acquisition for this sensor in the preferences of the application.

Frequently Asked Questions

Which hardware is supported by the application?

This question cannot be answered in general because Apple very often performs "silent product updates" that change the technical specifications of a model series without notifying customers. Some computers of the Apple Cube series for example are capable of providing temperature values while others are not.

Temperature sensors can also be part of graphics cards and hard drives. These components can also be different from computer to computer. To test whether Temperature Monitor or Hardware Monitor are supporting your system there is no other solution than to start one of the applications and have your computer analyzed by the program.

We are trying to support all Macintosh models that are capable of providing sensor readings. The application supports more than 100 built-in sensor types used by Apple and more than 200 sensor types used in hard disk drives.

What is a S.M.A.R.T. hard disk sensor?

S.M.A.R.T. is the abbreviation of Self Monitoring, Analysis, and Reporting Technology . It is an industry standard introduced in 1992 to react earlier on hard disk failures. A hard disk supporting the S.M.A.R.T. standard monitors itself with its own micro processor and allows the operating system to request readouts that indicate whether operational parameters have changed in such a way that the hard disk might become defective in the near future. In this case the hard disk can be replaced before any data is lost.

Some hard disk manufacturers allow the computer to request additional detail information, e.g. the current operating temperature of the disk. However, this feature is not an official part of the S.M.A.R.T. standards. Not every disk supporting S.M.A.R.T. is capable of providing temperature readings. Either the data is not measured at all, or the hard disk manufacturer did not publish how the data can be read out from the disk controller.

Temperature Monitor and Hardware Monitor analyze all hard disks connected to your computer if they include accessible temperature sensors. Each disk is tested for compliance with the S.M.A.R.T. standard. If the disk is supporting S.M.A.R.T. and the procedure for reading the temperature value of this particular model is known, the readings are automatically acquired by the software.

No sensors have been found in my computer. Can support for my computer be added to the program?

If this is an older computer, the answer will be "no" in nearly all cases. If this is a computer released a short time ago, the answer will be "yes" in most cases.

Computers built by Apple before 2002 are usually not equipped with sensor technology and therefore cannot be supported. In a few cases, sensors are indeed available, but they are not accessible by Mac OS X. Not the operating system but a self-contained control device monitors the readings in this case.

I am using the latest release of the application which should support my computer, but still no sensor at all, or only a S.M.A.R.T. hard drive temperature sensor is found. Is this normal?

Unfortunately there are some specific Macintosh systems which don't allow that sensor values can be read out by a normal application program. There are two different cases:

In both cases, it is not possible to develop an application program which could read out sensor values. The following Macintosh systems are affected by this problem:

Why are two hard drive temperature sensors displayed for my iMac G5? It has only one hard drive!

The iMac G5 may have two temperature sensors for the hard drive (depending on the drive model) although it contains one hard disk only. The sensor labeled as S.M.A.R.T. hard disk sensor is the internal temperature sensor provided by the hard drive vendor. The sensor labeled Hard Drive is the sensor provided by Apple. Apple's sensor is mounted at the outer metal frame of the drive carrier unit and measures the temperature of the air flow produced by the drive cooling fan. The S.M.A.R.T. sensor is located inside the drive unit, so its temperature is usually some degrees higher.

Why is no temperature displayed for my external FireWire or USB hard disk?

Nearly all FireWire or USB hard disks are in fact ATA hard disks accessed via a "FireWire/USB to ATA bridge device". Those bridge chips only translate a subset of the ATA commands between the FireWire/USB and the ATA protocol standards. In particular, commands to transfer S.M.A.R.T. diagnostic data (which are needed to access the temperature sensors inside the drives) are usually not supported. For this reason it is technically impossible to transport temperature data across a bridge. There will be a future industry standard called "Smart Command Transfer (SCT)" which will address this issue. But it will take some time before Apple and the hard disk vendors can fully support this.

Use the menu item Window > Show Drive Overview or Press ⌘+8 to display the transport protocols of all disk drives and their S.M.A.R.T. capabilities.

I own a very new Macintosh model which appears to be not correctly supported by the application yet. Will support be added?

Yes, if the model is equipped with sensors, we will add support as soon as possible. Please note that there can be a delay. Apple very often publishes products in Europe much later than in the US. We can only add support for a particular model if this model is available in Europe and can be tested.

You can support us in analyzing new systems by using the Submit Compatibility Report feature of Hardware Monitor.

My computer can display the CPU temperature using a program running on Mac OS 9, or using a special software for an upgrade CPU card with Mac OS X, but the monitor application does not find any sensors. It this an error?

This can only happen for computer models that either are using very old processor models which estimated their internal temperature via an inaccurate Thermal Assist Unit (TAU) but not a real temperatur sensor, or for computer models having a processor card of a third-party manufacturer which uses its own drivers.

If you are using a third-party processor card and temperature values can be displayed by special software, the manufacturer of this card has to publish a driver which is compatible with Mac OS X and makes temperature readings publicly available. After that, the sensor will be automatically detected by the application and values can be displayed. Card manufacturers can contact us for receiving more technical information.

Note that we cannot support upgrade processor cards from manufacturers that do not disclose technical detail information about their products. Some companies want to sell their own temperature monitor software and make sure their sensors cannot be accessed openly.

I am running the program on an x86-based computer which has not been manufactured by Apple. Only sensors for hard drives, batteries, and Intel CPU monitoring are displayed, but no other values. Can you add support for the other sensors of my mainboard?

This is only possible if the manufacturer of your system or your mainboard develops a driver for the sensors that is compatible with Mac OS X. Manufacturers can contact us for receiving more technical information

The sensor X shows the reading Y. Is this normal?

If you want to find out whether a sensor value is within normal limits, please select the menu item Window > Show Overview (or press ⌘+1) and look for the limits in the third and fourth column of the sensor table. They contain the known official limits Apple has specified for readings acquired at the given sensor locations. If no limit is given in the table, this either means that it does not make sense to specify a limit for this particular sensor (e.g. the battery capacity should not have limits), or Apple hasn't published any specifications for this sensor.

Note that all up-to-date Macintosh models automatically shut down or enter sleep mode if one of the readings exceeds a critical limit. For this reason it is impossible that your computer can be damaged in an overtemperature condition.

For old computers without temperature managment, no limits have been specified by Apple. In this case use the following limits as orientation:

Why is my hard disk not put into sleep mode if the application is running?

If one or more hard disks are equipped with temperature sensors, the values will be read out in regular intervals. Mac OS X is interpreting this as access to the hard disk which causes the disk not to be put into sleep mode.

You can change this behavior by enabling the disk saver feature of the application: When you are inactive and the computer is not really in use for some period of time, the program can automatically stop all sensor communication with your hard drive(s). This allows the standard sleep feature of the hard drives to become active. Just open the preferences window, go to the General pane and set the pop-up menu of the option Disk Saver to the desired time-interval for user inactivity.

Why is only one temperature value displayed for my dual G4 computer? It has two CPUs.

The temperature value is not measured by the processor itself but by an external sensor. For the "Power Mac G4 (Mirrored Drive-Doors)" this sensor is located at the center of the processor board. Only one sensor is available even if there are two processors on the card.

Why do the power sensors of the Power Mac G5 slots not carry a unit?

At this time we don't have enough data about these sensors. For this reason it is unknown in which unit the readings have to be interpreted. The readings could, for example, be interpreted as milliwatts. The sensors Slot 12V, Slot 3.3V and Slot 5V show the power load drawn by PCI cards for the respective voltages. The sensor Slot combined also includes the current power load by the SATA hard disks.

Why do the readings for the temperature sensors "Processor Card x Ambient" found in some PowerMac G5 systems never change?

Mac OS X does not seem to refresh these sensors on a regular basis. The system also ignores explicit commands to get new readings from these sensors. It is necessary to restart the computer or to put it to sleep mode temporarily to get up-to-date values.

The application displays a warning that I am using an Intel CPU with out-of-date microcode and that the per-core temperature sensors may stop working after the system is waking from sleep mode. What should I do?

This problem is caused by an internal design flaw affecting the first generation of Intel Core processors. The Digital Thermal Sensors may stop working when the processor returns from a C3/C4 power saving state. Intel has corrected this hardware bug in later versions of the CPU.

As a workaround, you should install Apple's firmware updates for your particular Intel-based Macintosh model. This will fix the problem in most, but not all cases. It is recommended to install the firmware update for the Boot-ROM, as well as the firmware update for the System Management Controller (SMC). To download the firmware updates from Apple, please see the following table:

Macintosh Model
Firmware Update
SMC Firmware
iMac (early 2006)
Mac mini (early 2006)
MacBook Pro 15" (early 2006)
MacBook Pro 17" (early 2006)
MacBook (early 2006)

NOTE: Macintosh systems built after September 2006 are no longer affected by the aforementioned problem.

Intel refers to this hardware problem as Erratum AE18. For detailed information, please see Intel document 30922204.

What does it mean if the reading for an internal temperature sensor of an Intel processor is being displayed as "---"?

This indicates that the application has no longer received up-to-date values from this sensor for a certain amount of time. This is normal if you have switched off the respective CPU core. Under specific circumstances, this can also happen if the system is under very low or very high CPU load. Note that Intel recommends a default access interval of 82 seconds to read out and use data of thermal processor sensors, so continuous monitoring of these sensors is not really critical.

Why are the temperature values for some of my FB-DIM modules in the Mac Pro or Xserve missing while others are displayed fine?

This indicates that you are using FB-DIMMs which are not fully compatible with Macintosh systems. In most cases this is caused by errors in the firmware of the AMB chip (Advanced Memory Buffer) controlling the module. You should replace these incompatible modules: If your system is not receiving valid temperature readings from the FB-DIMMs, the cooling control for the RAM temperature zone won't work correctly.

I get readings of more than 90°C (194°F) for the FB-DIM modules in my Mac Pro. Isn't this a bit high?

No, temperatures in that range are normal for FB-DIMMs and are no cause for concern. Each FB-DIMM contains its own controller, called "Advanced Memory Buffer (AMB)". An AMB also contains an internal sensor which measures temperature directly inside the chip. The specified maximum temperature
range of an FB-DIMM, measured by the AMB, usually lies in the interval between 95°C and 125°C (203°F .. 257°F). It will vary from manufacturer to manufacturer, a typical value is 110°C (230°F). If you like to know the exact specifications for your FB-DIM modules, note the part number and manufacturer of the respective modules (printed on the label of each module), and download the data sheets for that parts from the manufacturer. Nearly all chip manufacturers and RAM vendors publish the specifications at their web sites.

After upgrading the firmware of a FirmTek® interface card, the application can no longer display the temperature readings of hard drives connected to that card. Can you fix this?

No, a thorough analysis of this problem showed that after upgrading the firmware to version 5.3.1, certain FirmTek interface cards in certain configurations can no longer transfer specific response information from the drives back to the computer. This includes data necessary to display temperature readings in the monitor application. Try either to downgrade the firmware, or contact FirmTek to find a solution.

I don't see any core temperature sensors for my Intel-based Mac although I have installed the driver for extended x86 sensor support. The sensors have been visible in version 4.4 of the application and on my older Intel-based systems. Is this a problem with the program?

No, this indicates that your system is equipped with the third generation of Intel Core processors, using 45 nm technology. As confirmed by Intel, the Digital Thermal Sensors (DTS) which measure the core temperatures no longer behave linear enough in this processor generation to be used to display absolute readings in low temperature ranges. The readings are too inaccurate to be useful. Only in high temperature ranges where the core is about 20 centigrades below its specified maximum temperature limit, the sensors can be used to detect overtemperature situations. For this reason, Temperature Monitor will completely suppress display of core sensors for the affected processors. Hardware Monitor will display them as status sensors that give the reading "0" if the temperature is acceptable, and "1" when a core enters a critical temperature range and is about to overheat. Note that you can still monitor temperature readings per processor (not per core).

You can enable inaccurate temperature display for the affected processors for testing purposes. However, we don't recommend nor support this:

  1. Ensure that the driver for extended x86 support is installed and quit the application.
  2. Open a Terminal window and enter one of the following commands:

When using Hardware Monitor:

defaults write com.bresink.system.hardwaremonitor EnableCoreTempReadingsForCPU10670 1

When using Temperature Monitor:

defaults write com.bresink.system.tempmonitor EnableCoreTempReadingsForCPU10670 1

To return to normal operation, quit the application and use one of the following commands:

defaults delete com.bresink.system.hardwaremonitor EnableCoreTempReadingsForCPU10670

defaults delete com.bresink.system.tempmonitor EnableCoreTempReadingsForCPU10670

Why do some PowerMac G5 systems with 4 CPU cores sometimes not display values for their second cooling pump?

Apple distributes two different versions of the "quad" PowerMac G5 computers: Some of them are equipped with two pumps for the liquid cooling system, while others contain a revised version of the cooling system with only one pump. Hardware Monitor correctly reflects the situation for each version. If the sensor for the second pump is missing (label "CPU B Radiator Pump"), your computer uses a liquid cooling system with one pump only.

I have disconnected a fan cable or completely removed a fan in my Mac. Hardware Monitor still displays changing sensor values for this fan however. How is this possible?

Depending on the hardware model you are using and on the version of Mac OS X currently running, the operating system may not allow than an application program (like Hardware Monitor) gets access to the input values sent by the fan sensors. To get a reading nevertheless, Hardware Monitor then tries to get the output values the cooling control system sends to the fans.

Under normal circumstances, there is no difference between the input and the output values: If a fan is present, it will automatically follow the output value within a few milliseconds. However, when you remove the fan or the sensor, you are getting a "ghost" reading.

How can I check if Hardware Monitor would detect more sensors for my computer than Temperature Monitor?

Simply start the Hardware Monitor application. The sensors detected additionally will be listed in the window Running in Demo Mode.

How many registration keys do I have to purchase when monitoring several computers with the remote access feature of Hardware Monitor?

There is one simple rule: You need one registration key for each computer that is monitored at the same time.

Registration keys for Hardware Monitor and Hardware Monitor Remote are interchangeable. So if you are running Hardware Monitor and Hardware Monitor Remote on one computer you'll need only one key for this system. If another copy of Hardware Monitor connects to this system, it will need a second key because then we'll have a network of two monitored computers which are in use at the same time.

Another example: You have 2 computers that should be capable of monitoring each other. In this case you install the applications 4 times (a copy of Hardware Monitor and a copy of Hardware Monitor Remote on both systems), but you only need to buy 2 registration keys.

How can I configure Hardware Monitor to automatically warn me when a disk in a RAID set is failing, or a drive is no longer passing its S.M.A.R.T. self test?

This can be done in two simple steps:

  1. Open the pane Probes in the Preferences window of Hardware Monitor and create a RAID or SMART probe for the drive in question.
  2. Go to the pane Alerts, use the + button next to the table of sensors to be monitored and drag the newly created probe entry from the drawer into the table. Make sure the entry is still selected, remove the checkmark at Trigger alarm: When value exceeds threshold of, and set a checkmark at Trigger alarm: When value falls below, entering a value of 1.

You can then select which of the possible alert actions should be taken. If you want to continuously monitor the drive, it is recommended to add Hardware Monitor to your list of login items.

I have removed the application from an Intel-based system but have forgotten to use its function to deinstall the driver for access to the internal processor sensors beforehand. Can I remove this driver manually?

Yes, this is possible. Make sure you are working as user with administrative permission and remove the folder

/Library/StartupItems/BRESINKx86Monitoring

at the highest level of your system volume. The driver will become inactive the next time you start the operating system.