Evaluating the Intel Pentium M Processor Platform for Measurement and Automation

The performance requirements of measurement and automation systems continue to increase. Simultaneously, developers of these same systems are expected to hold the power consumption steady, if not decrease it. This puts the developers of measurement and automation systems and hardware in a challenging position. They must use components and platforms that deliver this delicate balance between performance and power consumption.

The Intel Pentium M Processor Platform

One platform that has been successful at achieving this performance/power balance is the combination of an Intel Pentium M processor and a member of the Mobile Intel 915 Express chipset family. Numerous performance-enhancing features have been implemented, while consuming less power than previous-generation platforms. Intel Pentium M processors offer a high-performance core architecture that implements, among other techniques, micro-op fusion and advanced stack management to increase performance. The Level 1 instruction and data caches are each 32 KB. With the size of these caches, you can access instructions and data quickly. Intel Pentium M processors also offer 2 MB of L2 (level 2) advanced transfer cache (ATC). The advanced branch prediction architecture reduces the number of branches that are mispredicted by selecting optimal algorithms, and data prefetching reduces the amount of system memory access that is required by prefetching data to the L2 cache. Additionally, the streaming SIMD extensions 2 (SSE2) instruction set improves performance by reducing the number of instructions that are required to execute program tasks. [1]

The Mobile Intel 915 Express chipsets include a 533 MHz front side bus (FSB) that enables a high-bandwidth connection between the processor and the chipset. Dual-channel DDR2 (double data rate 2) 533 MHz memory provides an improvement of up to 60 percent in peak bandwidth over DDR memory. The Mobile Intel 915 Express chipsets include the new PCI Express bus architecture, which provides the I/O bandwidth required by today’s high-throughput peripherals; the chipsets also include integrated Hi-Speed USB 2.0 for interfacing with peripherals. The direct media interface (DMI) provides up to 2 GB/s of concurrent bandwidth between the graphic memory controller hub (GMCH) and the I/O controller hub (ICH) and a 4x improvement over previous-generation interfaces. Moreover, the Intel GMA 900 (graphics media accelerator) delivers a performance improvement of 2x over previous-generation chipsets. [1]


One measurement and automation standard that employs the Intel Pentium M processor platform is PXI. The features provided by the Intel Pentium M processors and Mobile Intel 915 Express chipsets are ideal for this high-performance platform.

PXI – Employing the Performance of the Intel Pentium M Processor Platform

PXI (PCI eXtensions for Instrumentation) is a PC-based platform for measurement and automation systems. PXI combines PCI electrical bus features with the rugged, modular Eurocard mechanical-packaging of CompactPCI, and then adds specialized synchronization buses and key software features, with the result that PXI is both a high-performance and low-cost deployment platform for measurement and automation systems. These systems serve applications such as manufacturing test, military and aerospace, communications, automotive, machine and industrial control, and industrial test.

All PXI systems include a controller. Controller options include both remote control from a standard desktop PC and high-performance embedded controllers. Embedded controllers eliminate the need for an external PC, therefore providing a complete system contained in a PXI chassis. PXI embedded controllers are built using standard PC components in the compact PXI form factor.

The National Instruments PXI-8196 embedded controller uses the Intel Pentium M processor 760 and the Mobile Intel 915GM Express chipset. Intel Pentium M processors deliver higher performance than previous-generation processors, but at lower clock rates. The Intel Pentium M processor 760 operates at a clock rate of 2.0 GHz. The overall performance of the NI PXI-8196 is more than 50 percent greater than that of the National Instruments PXI-8187, which uses a 2.5 GHz Intel Pentium 4 processor -M. The SYSmark 2004 Overall Performance benchmarks for the PXI-8196 and PXI-8187 are provided in Figure 3. The PXI-8196 provides a 51 percent overall performance increase over the PXI-8187, even though it operates at a lower clock rate. Furthermore, the PXI-8196 requires less power than the PXI-8187.


To further compare the performance of the PXI-8196 with that of previous-generation controllers, a modular instrumentation system comprised of two National Instruments PXI-5122 high-speed digitizers was used with both the PXI-8196 and the National Instruments PXI-8186 embedded controller to acquire 3000 samples from multiple channels. The acquisition was performed using National Instruments LabVIEW graphical development environment. After data was acquired with the PXI-5122s, it was read into LabVIEW and a fast Fourier transform (FFT) was performed to analyze the frequency and phase content of the data.

Table 1 contains the average times required to read the acquired data into LabVIEW and perform an FFT for three iterations of each configuration with both the PXI-8196 and the PXI-8186. Even though the PXI-8186 uses a processor with a higher clock rate, a 2.2 GHz Mobile Intel Pentium 4 processor -M, the average decrease in execution time, and thus performance increase, when using the PXI-8196 instead of the PXI-8186 was 51 percent. These benchmarks represent a common measurement and automation application.

The Mobile Intel 915GM Express chipset supports dual-channel DDR2 SDRAM operating at 533 MHz, which is used in the PXI-8196. DDR2 is the latest memory technology, providing a peak bandwidth of up to 8.5 GB/s, which is up to a 60 percent improvement over the previous generation of memory technology (DDR SDRAM) [1]. The PXI-8196 has two SO-DIMM sockets and supports up to 2 GB of DDR2 memory.

The PXI-8196 dual-channel DDR2 memory makes the controller ideal for data-intensive applications that require significant analysis. Additionally, many measurement and automation applications configure buffers in memory. These buffers are used to store data before it is output to modular instruments and data acquisition modules and as the location where data that is arriving from these devices is initially stored. With up to 2 GB of memory, you can create large buffers, and with the bandwidth of dual-channel DDR2 memory, you can write data to and read data from these buffers at very high rates.

PCI Express – Bus Architecture for Gigabit Ethernet and ExpressCard

The Mobile Intel 915GM Express chipset includes the new PCI Express bus, which can be used to provide an interface to peripherals that require high bandwidth. On the PXI-8196, one of these peripherals is the Gigabit Ethernet port. Because it is implemented through the PCI Express bus, the throughput of the Gigabit Ethernet port is not limited by its connection to the chipset. Thus, it is capable of operating at the full specified rate. Gigabit Ethernet provides a high-speed communication interface for networking measurement and automation systems.

The ExpressCard slot on the PXI-8196 is also implemented through the PCI Express bus. ExpressCard uses the PCI Express and USB 2.0 serial interfaces to provide up to 2.5 Gb/s of simultaneous throughput in each direction. The ExpressCard slot can be used to add a second Gigabit Ethernet port to systems or additional peripheral I/O such as Serial ATA hard drives, 802.11 wireless LAN, removable flash memory, IEEE 1394 (FireWire), and Bluetooth.

The PXI-8196 includes four Hi-Speed USB 2.0 ports integrated into the Mobile Intel 915GM Express chipset. With Hi-Speed USB, you can achieve data transfer rates up to 15x faster than full-speed USB, while maintaining backward compatibility with both low and full-speed devices [1]. You can use the Hi-Speed USB 2.0 ports on the PXI-8196 to interface with external USB instrumentation, as well as to connect a keyboard, mouse, or other peripherals to measurement and automation systems.

Conclusion

The Intel Pentium M processors and the Mobile Intel 915 Express chipsets constitute a platform ideal for controlling today's sophisticated measurement and automation systems. From the high-performance core architecture of a Pentium M processor to the PCI Express bus of the Mobile Intel 915 Express chipsets, this platform delivers a superior balance between performance and power consumption. The National Instruments PXI-8196 embedded controller uses the Intel Pentium M processor 760 and the Mobile Intel 915GM Express chipset to deliver the power of this platform to PXI measurement and automation systems.


[1] Intel Centrino Mobile Technology Performance Brief, http://www.intel.com/performance/resources/briefs/mobiletechnology.pdf

Performance tests and ratings are measured using specific computer systems and/or components and reflect the approximate performance of Intel products as measured by those tests. Any difference in system hardware or software design or configuration may affect actual performance. Buyers should consult other sources of information to evaluate the performance of systems or components they are considering purchasing. For more information on performance tests and on the performance of Intel products, visit http://www.intel.com/performance/resources/limits.htm.

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Portions Copyright © 2005, Intel Corporation. All rights reserved.

LabVIEW, National Instruments, and NI are trademarks of National Instruments. Intel and Pentium are trademarks or registered trademarks of Intel Corporation or its subsidiaries in the United States and other countries. Other product and company names listed are trademarks or trade names of their respective companies.

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Related Links:
NI PXI-8196 2.0 GHz Pentium M 760 Embedded Controller for PXI
What is PXI?

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