Wednesday Oct 10, 2007

Open Standard I/O

    I changed roles at Sun, and am now a Technical Specialist focusing on our x64 technologies. While there is always an element of time spent on both customer relationships and technical skills development in pre-sales engineering roles, I prefer a balance more weighted towards technical depth and skills development/maintenance. I've always felt that as a technical professional, you have more credibility if you have spent at least some time working with the technology and products.

    Part of coming up to speed in a new role is getting a better understanding of the available resources. An important resource for sales is the ever present presentation. And while I appreciate the efforts of marketing to help promote our products, I need to be prepared to avoid potential rat holes by knowing the details of the background material used in developing the slides. If I'm hemming and hawing when presenting because I don't have confidence in the slides, I loose credibility. I get particularly wary when ambiguous or overloaded buzz words are used, such as 'open', 'free', 'grid', 'utility computing', 'blade computing', etc.

    Can you believe it, it took me 2 paragraphs to finally get to the meat of this post? :-) Sun has an impressive family of modular computing systems, or blade computers as they are commonly characterized. Among the many values of our modular computing family is the use of industry-standard open I/O. Ah, buzz words. What does that mean, industry-standard open I/O, and what is the benefit? It means that our compute modules use the same industry-standard open I/O technologies that our rack servers use, PCI-Express (PCIe). Instead of having I/O daughter cards on the compute module itself, that then need to connect electrically through the backplane to an I/O card in the chassis, making maintenance and reconfiguration more difficult, we pass the PCIe lanes through the passive backplane to PCI-SIG industry-standard PCIe Express Module slots at the back of the chassis. Simpler and more reliable.

    What is the benefit? There are several. Since the PCIe Express Module slots are separate from the compute module, you can easily hot swap PCIe Express Module cards, without needing to power down and remove the corresponding compute module, enhancing tool-less maintenance. Instead of having to remove the compute module, swap a daughter card and also swap an I/O card in the chassis, you can just swap the I/O card in the chassis. Fewer steps, less chance for human error, quicker. Sounds good to me.

    By sticking with industry-standard I/O, compatibility with 3rd party cards is enhanced, as is design and testing. PCIe is a well established standard, developed by a group of companies, and based on years of experience with previous generations of I/O interfaces. There are chip sets implementing the PCIe standard from several companies, and a well developed ecosystem of people and resources with the skills for designing it into systems. This makes it easy for 3rd party companies and partners, like QLogic, to develop cards for use in these modular systems, and the cards are compatible with other vendor's systems. For instance, I understand that NEC and Fujitsu use PCIe Express Modules for some of their systems, and others are planning on using this standard.

    Another benefit of using an industry-standard I/O technology is that as technology gets enhanced, and it inevitably does, maintaining compatibility is easier. Our implementation of the PCIe industry-standard I/O technology is forward-compatible with PCI G2 and IOV, adding to the investment protection provided by Sun's modular computing platforms. Building systems that take advantage of the well established design and years of testing experience of industry standard open PCIe makes for higher reliability and more choice, something I can talk to customers with confidence about.

A place where Perley Mears sounds off on topics relevant to his work at Oracle.


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