Peter Robinson of AMD and I had a wonderful chat about AMD’s latest offering as well as the pros and cons of the Apple video iPod that we both had. It also turns out Peter used to live around the corner from me. Yardley is a small place.
Anyway, on to the 64-bit craze. Most everyone should be familiar with AMD’s 64-bit architecture that includes the Athlon, Turion, and the dual-core Opteron (see Fig. 1). The big news is that a number of these chips and others in AMD’s product line (like the Geode) are guaranteed to be around for at least seven years, a critical consideration for embedded board developers. AMD has also significantly beefed up their marketing and support on the embedded side. In fact, there was some immediate payoff even at Bus and Board with some companies showing boards with AMD processors on them, like Performance Technologies’ CPC5565 CompactPCI board with a 1.8-GHz dual-core Opteron.
Peter and I discussed a number of interesting aspects of AMD’s 64-bit architecture, which is based on HyperTransport. This point-to-point interconnect can be used to build a mesh of multiple-processor Opteron systems by using the chip’s three HyperTransport links. The DirectConnect technology not only provides connectivity but creates a NUMA (non-uniform memory architecture) system where each processor shares its memory with other processors in the system. The HyperTransport links are tied directly into the memory controllers so latency can be minimized and throughput maximized.
HyperTransport can also be used for peripheral connections. This is key for embedded systems like those presented at the Bus and Board show, since HyperTransport can be used to link a processor on the motherboard (actually a blade) and peripherals like an FPGA on a VITA 42.4 mezzanine card. Of course, there could also be another processor on the card.
HyperTransport already has the standard HTX connector that has been primarily used for an InfiniBand host adapter in supercomputers. Peter indicated that the same kind of link can be used to tie boards or blades together—similar to HTX and VITA 42.4—allowing an incremental increase in performance through the addition of more processors. This could have an interesting impact on the design of upgradeable embedded systems.
The other news was related to power consumption. There are now versions of single-core processors with a power envelope of 30 W, 55 W and 95 W with dual cores coming in at 55 W and 95 W. This is important in board systems where 100 W or 200 W is the upper limit on cooling.
AMD is doing some interesting things with HyperTransport and its partners. For example, Broadcom’s HT-1000 is a host-based RAID 5 SATA controller and PCI Express interface that links to the system via HyperTransport.
Expect to see AMD processors showing up in other board systems such as AdvancedTCA boards and VME boards.
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