Embedded Intel

Embedded Intel Solutions

PCI Express Versus RapidIO: The Winner Is...

By Dave Barker, Extreme Engineering Solutions (X-ES)

The debate known as the “fabric wars” started around the turn of the century and has been raging ever since. Over the past decade, there have been dozens of entries vying to be the system-interconnect fabric for embedded systems. Who can forget Advanced Switching Interconnect (ASI), StarFabric, Hyper Transport, InfiniBand, and Parallel RapidIO? Now, the list of contenders is down to just three: 10 Gigabit Ethernet (10 GbE), RapidIO, and PCI Express (PCIe).

Ethernet isn’t going away. RMDA support is part of the 10 GbE specification and cut-through switches are becoming available. (Here, the switch starts forwarding a packet before the whole packet has been received, as opposed to store-and forward switches.) Clearly, 10 GbE will serve the needs of many applications. It will take some time, however, before 10 GbE is ready for the heavy lifting of the data plane for highend applications.

Until then, RapidIO and PCIe are the most viable highperformance, low-latency, low-overhead, embedded-systems interconnects. RapidIO has been seen by many to be technically superior—primarily because of its peer-to-peer support. PCIe was designed as a serial replacement for the parallel PCI bus. At the software level, PCIe preserves compatibility with PCI. To use PCIe in embedded applications with multiple,independent CPU subsystems, non-transparent bridging is required (just as CompactPCI required non-transparent PCI bridging).

To read more, click the link below

 Embedded Intel