IBM has published a statement of direction on its web site that starts to spell out the direction it’s going with the System i. Hat tip to IT Jungle for pointing this out. Here are the statements, step by step:
If you want to upgrade from a Power5 machine to Power7, the only way you can preserve the serial number is by first upgrading to Power6, and then to Power7. Why is the serial number important? From IT Jungle:
This serial number thing is important for the accountants and the tax man. (If you don’t preserve the serial number, you have to write off the full value of the initial asset at the time of the upgrade.)
Power7 hardware will support the existing 12X I/O drawers, according to the statement of direction. Older I/O drawers that were supported on Power6 and earlier hardware — RIO/HSL-attached I/O drawers — will not be supported. In the statement, IBM “suggests” that Power6 users upgrade to the 12X I/O drawers now in anticipation of an eventual upgrade.
IT Jungle calls 12X I/O drawers “gussied up” InfiniBand, and had this to say about the potential future of I/O on i:
I think IBM will have to move to QDR InfiniBand for I/O drawer links for a simple reason. The PCI-Express 2.0 peripheral slot standard has a peak data rate of 40 Gigabits/sec. If you don’t have a faster and wider network pipe, the I/O is going to flood it. And when the I/O pipes are flooded, expensive multicore processors like Power7 chips spin their cycles and do not work. As a wise man once said, all computers wait at precisely the same speed. . . . And waiting is the one thing system engineers have to design out of the box.
The statement of direction also says that Power6 machines will be the last hardware to support a number of storage and networking technologies: SCSI drives that are 36 GB or less or 10K RPM SCSI drives; quarter-inch cartridge tape drives, and I/O Processor (IOP) and IOP-based PCI cards.