Providing software "knobs and dials" is a different way to handle thermal management on board level products. Most cooling strategies for hardware involve intricate heatsinks, extensive fan systems, or even complicated conductive cooling packages. With the 3rd Generation Intel® Core™ processors, there are more processor management options available through software that gives system designers and users more control than ever. As discussed in my November 12 posting, Roving Reporter: BIOS suppliers respond to manipulating the BIOS to affect cooling, the BIOS suppliers have taken steps to leverage features in 3rd Generation Intel® Core™ processors, for instance, the Enhanced Intel SpeedStep® Technology and Thermal Monitoring Technologies. But what are the hardware suppliers doing to take advantage of the work done by the BIOS suppliers?
In the case of blade boards and systems, such as AdvancedTCA, the thermal management is responsibility is within the Intelligent Platform Management Interface (IPMI), a standardized computer system interface used by system administrators for out-of-band management of computer systems and monitoring of their operation. Intel was a key contributor to the development of the IPMI standard. In most IPMI supported systems is a separate Baseboard Management Controller (BMC) that is responsible for thermal management. It monitors thermal conditions and makes system adjustments to fans and processors in accordance to pre-set trip points either established through the BIOS or applications running on the operating system.
In most cases, advanced operating systems such as Windows 7 and later releases of Linux do most of the heavy lifting when it comes to thermal management and processor performance management. The operating system either communicates through the BIOS or in some specialized cases, directly to dedicated monitoring processors provided by the hardware vendors. But the general feeling is that there is an opportunity for the hardware vendors to enhance the manageability of thermal monitoring in new board products with Enhanced Intel SpeedStep® Technology and Thermal Monitoring Technologies.
The biggest breakthrough is the improved dynamic monitoring and response capability in 3rd Generation Intel® Core™ processors. This gives users much more capability than possible in previous generations. Thermal Monitoring extends the capability to monitor to new levels, potentially making it possible to simplify future board designs by reducing or eliminating the need for external thermal monitoring circuits that were implemented via various microcontrollers.
Here is a look at what several hardware suppliers are doing today.
Advantech has a very broad range of board level products from single board computers to blades, many of them using 3rd Generation Intel® Core™ processors. AdvancedTCA products utilize IPMI but where Advantech really views the advantage is with the configurable Thermal Design Power (TDP) options included with 3rd Generation Intel® Core™ processors. Many customer requirements exist that can leverage TDP so Advantech now offers a mechanism for implementing "reduced power modes". More specifically, they are implementing static as well as dynamic "reduced performance modes" that allow their customers to run systems in borderline conditions. For example, running processor blades in chassis’ that cannot provide adequate cooling for full performance modes or running systems with ambient temperature limits, the static cases. Or dynamically limiting power when a fan failure or other critical conditions (e.g. rising ambient temperature because of failing AC) are detected.
“There is a lot more thermal management technology available today than what is managed by the BIOS,” commented Thomas Kastner, x86 Software Architect, Advantech. “Configurable TDP allows us to implement thermal management in a low level and failsafe way that does not require OS support. Of course we have mechanisms to notify the OS about reduced performance mode being triggered, but the point is that we don't have to rely on power-management capable software (OS) for the actual control.” Architectures that use IPMI, BMCs, and now 3rd Generation Intel® Core™ processors give users very granular and dynamic thermal management capabilities.
The Kontron product line is very diverse covering many different platform technologies for many different markets. Many of the new computer platform products are now using 3rd Generation Intel® Core™ processors in several different configurations. Kontron subscribes to the use of the Advanced Configuration and Power Interface (ACPI) specification developed to establish industry common interfaces enabling robust operating system (OS)-directed motherboard device configuration and power management of both devices and entire systems. They expose key ACPI trip-points to allow the user to manage the processor and thermal responses.
“We often look at the needs of individual customers and work with them set up the best configuration for their application,” stated Steve Potocny, software engineering manager at Kontron. “Sometimes we use additional hardware devices to monitor and control the hardware so that the customer can set specific parameters that do not require operating system intervention.”
Radisys has developed the Radisys Embedded Software Platform (eSP) that encompasses EFI pre–boot environment applications, user BIOS customization tools, and standardized APIs for low–level functions. Designed primarily for their COM Express modules, eSP provides easy access to monitoring and control settings via its user–friendly Application Programming Interface (API) calls. An API is tightly written code that interfaces between the OS and BIOS to check or set specific functions. These APIs can save developers the time and effort of writing and testing the interface code, providing a tested and proven call routine. The Radisys APIs include access to board information, backlight control, I2C bus, GPIO programming, HW monitoring and setting the watchdog timer. New Radisys APIs are compliant to the PICMG EAPI specification for COM Express modules. The PICMG EAPI supports reading values for various processor, chipset, temperature, voltages, and fan registers. Here the user can monitor thermal trip points and control fan speeds.
Commented Scott Fabini, Radisys, “The demands on SWaP constrained products could certainly benefit from the ability to optimize thermal management and processor performance at any level, including the BIOS.” In addition to the capability build into the 3rd generation processors, Radisys adds additional sensors to the memory arrays to be sure that they are thermally monitored over a -40°C to 85°C operating environment.
Radisys includes temperature sensors on SO-DIMM memory modules, allowing the customer’s OS/application to monitor memory temperature, along with standard processor and system temperatures. This provides greater coverage to ensure the total solution remains within challenging temperature constraints found in aerospace and defense environments.
In summary, the general feeling I get is that there is still a lot of room for taking advantage of many of the new features in 3rd Generation Intel® Core™ Processor family when it comes to thermal management. Many hardware suppliers are comfortable with existing microcontroller strategies but they are studying how they can better leverage the Enhanced Intel SpeedStep® Technology and Thermal Monitoring Technologies in future designs.
Intel Embedded to learn more about BIOS support options.
Kontron whitepaper on Advanced Thermal Management Solutions, requires registration
You can also find more information on the Radisys eSP platform in the following article in the Intel Embedded Innovator Magazine: Minimizing Downtime in High-Reliability Systems
For more on energy efficiency, see Roving Reporter: Improved Energy Efficiency Can Eliminate Active Cooling Devices, Reduce Power Consumption, and Save Board Space
OpenSystems Media®, by special arrangement with Intel® Intelligent Systems Alliance