Kontron’s PCI Express Development Initiative
PCIe six-pack in time for Embedded WorldBy Norbert Hauser, Vice President Marketing EMEA, Kontron AG
In 2005, embedded computer technology will take a revolutionary step. PCI Express is about to replace the PCI parallel communications bus, which is more than 10 years old. The advantage of PCI Express (PCIe for short) is that the serial architecture reduces space requirements and power dissipation, while at the same time increasing bandwidth, thus improving the cost effectiveness and performance of embedded computer technology even further.
For this reason, Kontron has launched a development initiative in recent months, which is showing its first results in time for the Embedded World fair: no less than six PCIe boards will be introduced all at once. Besides the ETXexpress Computer-on-Module, which was announced a year ago, an AdvancedTCA blade, an AMC module (Advanced Mezzanine Card), a PICMG 1.0 full-size slot CPU assembly, as well as an industrial ATX, and an industrial micro-ATX motherboard will make their appearance.
The first applications to benefit from these boards are found where the newest peripheral interfaces are used. These appear, for example, in datacom and telecom (Gigabit Ethernet/Firewire), server applications, data storage, medical, gaming as well as in high end industrial applications such as image processing, frame-grabbing, or inspection systems.
How much these applications will benefit from PCIe can already be seen just from the bandwidth of Gigabit Ethernet (125 MB/s) in combination, for example, with ATA150 (150 MB/s). If the communication of both interfaces runs over a PCI Bus (133 MB/s), the maximum throughput (275 MB/s) can never be achieved. PCIe eliminates this bottleneck. A standard PCIe interface (PCIe x1) already offers 250 MB/s, after all - in both directions. Thus, this PCIe ‘lane’ has almost twice as much bandwidth as PCI and can handle the communication from ATA150 and Gigabit Ethernet without any loss of performance.
Furthermore, several lanes can be combined, giving PCIe an enormous additional performance potential. A x16 slot achieves a net maximum of about 4 GB/s per direction. That is 30 times the transfer volume of the PCI bus with 133 MB/s, and doubles to 60 times if the bidirectionality is counted. Moreover, in the future, PCIe cards will be hotswap-capable, which increases convenience, and will also communicate directly with one another, thanks to switch technology. As a result, they no longer need to put a strain on the processor. Furthermore, PCIe is software compatible with PCI, which simplifies the development of new PCIe-based assemblies. With this potential, PCIe is destined to become the dominant data path for the coming x86 systems.
Modular Blade for telecommunication infrastructure equipment
AdvancedTCA is dedicated to achieving the highest performance for telecommunication infrastructure equipment, and PCI on board would represent even more of a bottleneck here than in other applications, because communication via the backplane now only takes place in the gigabit range. Accordingly, the new ultra-high performance server blade AT8001 with Intel LV Xeon 2.8GHz processor and 800 MHz system bus naturally has PCIe on board. Furthermore, it is also the first on the market that supports the Advanced Mezzanine Card (AMC) specification. This makes the design of the AT8001 feature set particularly flexible, because the I/O functionality or the processor performance of the blade can be adjusted to meet requirements, depending on the AMC module installed. And, of course, AMC modules also support PCIe. Besides PCIe, the AMC slot also offers Gigabit Ethernet and SATA, so that from the blade to the backplane the AMC module always offers the highest bandwidth without changing the media.
Advanced Mezzanine Card for scaleable telecommunication performance
Furthermore, Kontron introduces the first AMC module with PCIe: the highly integrated processor module AM4001 - designed, though not exclusively, for the new AT8001 blade - is equipped with a 2.0 GHz Pentium M 760 processor and a maximum performance chipset, and supports the AMC.1 (PCIe), AMC.2 (Gigabit Ethernet) and AMC.3 (SATA) standards. All this and even more is offered on a mere 181.5 mm x 73.5 mm. The use of AMC modules on appropriate carriers significantly increases the scalability and flexibility in the system design, because an ATCA carrier can take up to eight AMC modules, depending on its layout.
Computer-on-Modules with PCIe
The use of Computer-on-Modules (COM) on appropriate baseboards and carriers significantly increases the scalability and flexibility in the system design, and also accelerates the time-to-market factor. Those are striking arguments for the use of COM in custom-designed embedded computer systems, and the growth rates in this market segment are correspondingly high in times of tough competition and tight budgets. To make PCIe available as quickly as possible on modules as well, Kontron already introduced a suitable concept a year ago with ETXexpress, which has now also become the open PICMG standard under the neutral name COM Express. In accordance with the PICMG COM Express standard, the first ETXexpress Computer-on-Module is equipped with the 2.0 GHz Intel Pentium M 760 processor and Intel’s first mobile chipset for PCIe. It offers eight PCIe x1 lanes for the connection of peripherals, as well as PCI Express graphics x16 lanes for graphics support. Additional features are Gigabit Ethernet and serial ATA. Moreover, eight USB 2.0 ports offer fast interfaces sufficient for external drives/Flash, keyboard, mouse and other peripherals.
Slot CPU assembly in accordance with PICMG 1.0
PICMG 1.0 compliant CPU boards dazzle with their simple system configuration, which is limited to the essential: computing performance. SlotCPU configurations are very attractive in terms of price/performance. One PICMG 1.0 can directly manage four PCI I/O boards - and even with this standard - PCIe is a real asset, although it is not directly accessible, and is available for the first time on the new slot CPU assembly PCI-955 for all high-speed I/O on board. Four PCIe x1 lanes offer a total of 2 GB/s internal bandwidth, which is available for 2x Gigabit Ethernet, PCI 64bit@66MHz and 4x SATA. Thus, board-internal communication is finally no longer the limiting factor. In addition, the graphics performance is also clearly improved. The processor is the energy-saving 2.13 GHz Intel 770 Pentium M. As an alternative, the 1.3 GHz Intel 320 Celeron M Performance can also be used. Besides two Gbit Ethernet ports, there are also 4x SATA, 6x USB 2.0, as well as two serial and one parallel port.
Two industrial motherboards
Industrial-grade motherboards are produced by Kontron for, among other uses, the gaming industry, medical imaging technology, and kiosk, infotainment and POS applications. Thanks to a market share margin that ranges from 35 percent in automation control functions to 58 percent in aerospace and defense technology, in comparison to alternative solutions, they offer the highest I/O performance, long-term availability of typically 3 years and revision control at the most attractive price. The new PCIe-based industrial-grade ATX motherboard 889LCD/ATX with Pentium 4 or Celeron processors is conveniently equipped with two PCIe x1 slots for I/O assemblies and one PCIe x16 slot for graphics or ADD2 cards, for example. Four classic PCI slots are also still available. Thus, the board is ideally equipped for the upcoming new PCIe expansion cards. The first available PCIe x1 expansion cards offer RAID, SCSI, SATA, Firewire, Gigabit LAN, video or frame-grabber functions, among others. Moreover, many high-performance PCIe x16 graphic cards are already available on the open market.
The smaller industrial Micro-ATX motherboard 889LCD/ATXU offers one PCIe x1 and one PCIe x16 and two PCI as standard interfaces. Other highlights of the board include eight USB 2.0 (four of them internal), one Gbit Ethernet and two SATA 150. The board is thus particularly interesting when the reduced feature set is sufficient, because then very compact systems can be built, which is definitely the trend.
PCIe will be everywhere
These six, for the most part very different, embedded computing form factors are the first platforms offered by Kontron for PCIe. Others will follow, one after another, this year. In the medium term, it is planned to make PCIe available for every suitable form factor. Depending on the form factor, however, it will take a while until this is implemented, because the slot interfaces for PICMG compatible slot boards, for example, are still being standardized. They are expected to be released, in all probability, after the end of 2005. However, the ISA bus still has not disappeared from the embedded world, so that PCI-based systems will still be of significance for a long time to come.