Monday, December 04, 2006

Are you ready for 5GHz?

The PCI Express 2.0 spec could be officially complete by the end of the year, laying down a path for 5GHz chip-to-chip signaling in a broad range of computer, communication and consumer gear.

I have two questions for you about that: Is there demand for this speed? If so, where is it? And what are the signal integrity issues computer, comms and consumer engineers face at this data rate?

Please c'mon back with some lively and substantive postings. Or if you are more inclined email me at --rbm


joe said...

Clearly demand for 5G in servers for storage connections. And maybe as a larger interconnect in blade servers. But 5G is nichy. Sort of like PCI-X - never made it to mainstream. PCI is about connectivity, not performance. 5G PCIe remains small.

Mike said...

In the client space, 5G is for graphics, graphics, and oh, wait, graphics. It is about performance pure and simple. Developers want to tap into the power that GPU deliver and add in new functionality at lower cost points. With a 5 GT/s x16, a GPU can use more host memory for its video needs allowing lower cost and high performance solutions to be delivered. This is exactly the message being pushed forward by AMD / ATI.

In servers, it is about performance as well but driven not just by storage (that is rather short sighted). It is driven by the need to support consolidation, virtualization, and high-speed IPC applications. Providing higher performance enables RASUM solutions at lower cost points since fewer links are needed.

There are simply so many good reasons to push to 5 GT/s. The challenge for the industry is recognizing that the need for speed has not changed since the introduction of PCIe or PCI-X 2.0. It remains solid and compelling with the same TCO and so arguments being true today.

Alan said...

What Mike said. Ditto.

On the Graphics side, both for traditional graphics/visualization and for GPGPU (compute), the on-board memory bandwidths are pushing 100GB/s while the interconnect is oozing along at 4GB/s.

There's also the bigger system interconnect side. As the interconnects get faster, the system as a whole can start looking like more like SMP systems of the '90s that we all loved.