IBM Will Fill The Hole In The Power8 Line

November 3, 2014 Timothy Prickett Morgan

The Power8 rollout has seen entry machines with one and two sockets, the so-called scale-out Power S-class machines. And IBM has just condensed the enterprise-class Power 770 and Power 780 machines with the high-end Power 795 to come up with the new scale-up or enterprise Power E-Class machines using the Power8 chips. But there is a pretty big hole in the middle between these two classes of machines, and one that IBM knows it has to fill before too long.

And the word from on high is that IBM will, indeed, fill the gap between the entry and enterprise class.

“There will be a four-socket system in 2015,” confirms Steve Sibley, director of worldwide product management for IBM’s Power Systems line. “We have not decided as yet whether we will have two models or just one. I am guessing that we will have an 750-class and it will have all of the capabilities of the 760 as well. That will come in the first half of next year.”

If history, and the naming conventions in the System z mainframe line are any guide, then the forthcoming midrange boxes will be called business class and have the letter B appended to their monikers. In this case, it would make sense to see what I am calling for the moment a Power B850 and possibly a Power B860, starting with two sockets and running up to four in a single chassis, with different peripheral expansion and perhaps different processor card options as was the case with the Power 750 and Power 760 machines that were based on the Power7+ chip and, incidentally, used dual-chip modules like the scale-out Power8 machines do.

Incidentally, this initial Power B850 system will not just be one of the nodes ripped from a four-node Power E870. That E870 has an architecture akin to the Power 795 in that it has a central system control unit with master system clocks and oscillators for controlling the timing of the system, an operator panel, field service processors, Hardware Management Console (HMC) ports, and a vital products data (VPD) card. It could end up that the Power B850 uses the same 5U chassis as the single node in the Power E870 system and has all of the extra electronic goodies extracted.

The Power 750+, you will recall, was based on an eight-core dual-chip module that had Power7+ processors running at either 3.5 GHz or 4 GHz. It came in a 5U chassis instead of the 4U chassis used with the Power 720+ and Power 740+ servers that had one or two sockets, respectively. The Power 760+ came in the same 5U chassis as the Power 750+, but it used Power7+ dual chip modules with a total of 12 cores per socket. Both the Power 750+ and Power 760+ had from one to four processor cards with one processor per card.

IBM is currently able to support up to 2 TB on the two-socket Power S824 using 128 GB custom DIMM (cDIMM) memory chips, but for the moment it is only supporting 64 GB cDIMMs on the Power E870 and E880 machines, for a maximum of 1 TB per socket or 2 TB across four sockets. My guess is that if IBM bifurcates the Power8 midrange into two machines–which did not seem likely according to statements made by Sibley above–is that a Power B850 would have the skinnier memory at 512 GB per socket and the Power B860 would come in with 1 TB per socket. This difference in memory configuration is exactly what IBM did is the same differentiation that IBM made between the Power 750+, which had 256 GB per processor card for a maximum of 1 TB, and the Power 760+, which had 512 GB per processor card for a maximum of 2 TB.

I have a hard time believing there were a lot of IBM i shops buying 1 TB or 2 TB of main memory, so the issue is really what do the 16 GB and 32 GB memory sticks cost and what customers can do with a 64 GB or 128 GB memory footprint on a midrange machine. This is not a lot of main memory by modern standards, but if you add flash to the system as well as disk you can get a pretty zippy server compared to a Power5 or Power6 machine that has a smaller memory footprint and a lot less computing power. The Power 550 is as much a target for these hypothetical and impending Power8 midrange machines as the Power 750, Power 750+, and Power 760+ boxes are. The question now is whether it will make sense for customers to move to a Power S824 instead of a Power B850 or Power B860 if one should materialize. The latter will almost certainly cost more per unit of compute and will almost certainly also be in a higher IBM i software tier, too. If anything, such a midrange box might eat into sales of Power E870 systems if customers decide to make a shift from disk to flash and from skinny to larger memory footprints in an effort to make full use of the processing capacity of their machines. This, I think, is why a midrange box was not yet announced. IBM wants to be able to soak up as many Power E870 sales as it can between now and whenever the Power B850, as I am calling it, starts shipping sometime in the first half of next year.

As for when that will be, my guess is sometime around April or May. The COMMON midrange conference is at the end of April, and that is the natural time to have such an announcement. The IBM Edge2015 conference, which sports Power Systems and System z announcements, runs May 11 through 16 as well, and that is another obvious time to do such an announcement. My final guess is that COMMON will get Technology Refresh announcements for the IBM i 7.1 and 7.2 operating systems and that Edge2015 will get the new midrange hardware.

At some point, we need to see some Flex System nodes based on Power8 chips, too. Unless IBM is less interested in that product line now that Lenovo is the owner of that converged system. I will try to get a feel for IBM’s plans here.

After that, all eyes will turn on what IBM’s plans are for Power8+ and Power9.

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