Temperature Monitor

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Temperature 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 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 columns 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 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 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 those parts from the manufacturer. Nearly all chip manufacturers and RAM vendors publish the specifications at their web sites.

I am using an Intel-based system of a model series which was announced after January 2008. Temperature Monitor can display the external CPU temperature but not the temperature values per core, even if I install the driver for extended x86 sensor support. Does this indicate a problem?

No, this is the correct and intended behavior for some specific Intel processors. When Intel introduced the third generation of Core and Core-based Xeon processors, manufactured in 45 nm technology ("Penryn" series), they also changed specific aspects how the Digital Thermal Sensors (DTS) on the chip cores are working. To check if your system is using a third generation Core processor, open the System Info window in the application and press the button More info… inside the window. A processor of this series will be identified as x86 Family: 6, x86 Model: 23.

If a processor of this series additionally identifies as being Xeon(R), it won't be possible to get an accurate per-core temperature reading. Those processors are equipped with Digital Thermal Sensors which do not work linear enough under normal operating conditions. They will only show accurate readings near the maximum allowed temperature limit. For this reason, Temperature Monitor won't display core temperature readings in that case.

If a processor of this series identifies as being a Core(TM) 2 Duo, it will depend on the exact CPU model. For the processor types in use by Apple, the applications should be capable of displaying core temperature readings. If you are using a CPU usually not found in Apple computers, the applications might not always be capable of displaying core readings.

When using an Intel Core 2 Duo processor of family 6 model 23 (see previous question) the temperature readings from the core sensors sometimes appear to be lower than the outer CPU temperature. Isn't this wrong?

This is the way the Digital Thermal Sensors and the temperature diode sensors are designed. The effect is caused by different policies used for the calibration of the sensors. The two types of sensors have different accuracies and are factory-calibrated to different maximum points. For this reason, the DTS reading cannot be used to predict the CPU case reading.

The application displays readings for twice as much processor cores as should actually be in my Mac Pro (March 2009). For my 4-core Mac, it displays 8 cores, for my 8-core Mac Pro, it displays 16 cores. Is this correct?

Yes, the new generation of Macintosh systems uses processors with Intel® Core™ i7 technology. By default, Mac OS X will enable a hardware feature called "Simultaneous Multi-Threading" when detecting these CPUs. Simultaneous Multi-Threading means that a single processor can dispatch two independent streams of instructions at the same time, so one physical processor can act as two processors. Mac OS X and all applications will behave as if twice as much processors are built into the computer. To display the true number of physical and virtual processors, select the menu item Window > Show System Info, or press ⌘+4. The line Number of processors will display how many physical and how many logical processors are available, and how many processors are currently actively in use by Mac OS X. The number of processor chips can be displayed by pressing the button More info… next to this line. By using the navigation buttons in the upper right corner of the processor details sheet, you can browse through all chips available. The program will display each chip with the title Unit x, where x is the current number of the chip package. Example: 8 processor cores, 16 logical processors, 16 actively in use, in 2 chips.

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. Is this a problem of the application?

No, this problem is caused by an incompatibility between the FirmTek/SeriTek drivers for Mac OS X with firmware version 5.3.1 or later. Only PPC-based computers are affected. To solve this problem, please download the latest available drivers from FirmTek.

I am using a Mac of a model series announced after October 2008. It has an integrated NVIDIA GeForce 9400M graphics solution. Many of the sensors for the graphics chips are sometimes displayed as being "disconnected" when I display their preferences in the Sensor section of the Preferences window. How is this possible?

If you are using a Mac of such a model series, your computer will in fact contain two different graphics chips: A low performance, low power graphics processor, the GeForce 9400M, which is an integrated part of the chip controlling the main logic board, and a second, discrete high performance chip, the GeForce 9600M GT. This combination of two graphics processors can operate in the following modes:

The sensors of the discrete GPU are switched off when that GPU is inactive. In this case the application must handle the sensors as being disconnected. This is the correct and intended behavior. When the integrated GPU is inactive, it is not fully switched off because it is part of the mainboard controller and has to pass-through the signal from the discrete GPU, so both sensor sets will be operational.

In some cases, your Mac might be in an aggressive power saving mode when starting the application, with the effect that the application may see both GPUs as being inactive. In this situation, the readings of all graphics processor sensors -with exception of the outer chip and heat sink sensors- will be suppressed. This affects the sensors named Graphics Processor Temperature Diodes in Temperature Monitor.

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.

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.