The new zSeries 890 was code-named Ptero internally at IBM. In keeping with the company’s ironic saurian naming scheme, this is short for pterodactyl, and like its older brother, the T-Rex zSeries 990, it is based on the G8 series of mainframe processors.
While the zSeries 890 shares much of the same technology as the prior zSeries mainframes, this new machine, which is being announced to much fanfare on the 40th anniversary of the launch of the System/360 mainframe, includes a new twist on a recurring theme of recent mainframe designs.
With the earlier G-series class System/390 mainframes from the 1990s, individual mainframes, comprised of multiple CMOS mainframe engines glued together with symmetric multiprocessing (SMP) electronics, could be linked together into parallel sysplex clusters to provide horizontal growth for MVS and OS/390 workloads. As IBM added more and more engines to the multichip module (MCM) processor complex, eventually it decided to use extra engines in the MCM as hot stand-bys in the event of a component failure or as capacity on demand. These standard processors could also be configured to run the special clustering code as a Internal Coupling Facilities. Prior to this, these clustering co-processors were whole separate computers.
Back in late 2001, IBM got the bright idea of making mainframe processors Linux-only and then charging a whole lot less money for those engines to try to spur demand for mainframe processing capacity. And it worked. About a fifth of the MIPS that IBM ships are now for the Integrated Linux Facility, as IBM calls mainframe processors that are dedicated only to Linux workloads. These Linux engines first came out with the Linux-only versions of the Raptor zSeries 800s, which made their debut at LinuxWorld in January 2002. Back then, a uniprocessor Raptor server equipped with a reasonable amount of memory and disk, the z/VM license (only good as a Linux partition manager) plus three years of maintenance and software services had a list price of around $400,000, and a uniprocessor Freeway zSeries 900 mainframe (the T-Rex machine was not yet announced) with the same features sold for around $750,000. It was obviously a lot cheaper to run Linux on a special Raptor Linux engine than it was on a real zSeries. The Raptors used the G7 class of engines, which were code-named Blue Flame and which were rated at between 250 MIPS for a 770MHz processor to 300 MIPS for a 950MHz processor.
With the zSeries 890 Ptero boxes, IBM is putting forth a lower-cost way of running Java workloads. This time around, IBM is taking a mainframe processor, slapping some microcode on it that allows it to support Java Virtual Machines, and designating it as a Java co-processor for other standard processors in the z890 complex. This Java processor, which is called a zSeries Application Assist Processor, or zAAP, is not running z/OS, z/VM, or Linux, so it cannot be used to do any other work, says David Mastrobattista, zSeries marketing manager.
However, on typical commercial Java applications, according to IBM’s analysis, these zAAPs can have anywhere from 50% to 70% of Java instructions run on them rather than on the standard processors. (Why it is not 100% is unclear, but perhaps some Java instructions take less time to run locally on the standard processors than it would take to move them over to the Java processors.) What this means is that companies can offload MIPS from a regular mainframe, which costs three to four times as much as a Linux or Java mainframe processor. This allows them to add Java to their workloads – something Mastrobattista says companies want to do – and get the reliability and sophisticated transaction monitoring capabilities of the mainframe. Otherwise, they would have to run WebSphere within a Linux partition on a mainframe, or offload WebSphere to a set of separate Unix, Windows, or Linux boxes linked to the mainframe. The Global 2000 customers who have lots of mainframes and like them want to add WebSphere, but they don’t like the high costs of putting it on a mainframe.
That’s why the zAAPs are going to be offered on the bigger T-Rex zSeries 990 servers, too. While Mastrobattista says that some customers will upgrade from prior mainframes with Java workloads and spend less money on z/OS operating systems as they move Java workloads to the co-processors, IBM is clearly gambling that customers will like the idea enough that IBM will sell a lot more mainframe engines. This strategy has by and large worked with Linux, and although Mastrobattista will not confirm that similar co-processors could be in the works for the mainframe (such as for DB2 processing or for TCP/IP networking), he concedes that this certainly is possible.
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The new zSeries 890 is based on a geared down version of the G8 processor that was announced in May 2003 running at 1.2GHz and delivering about 450 MIPS of processing power for the T-Rex mainframe. The T-Rex machine could cluster up to 32 of these processors together, and will eventually scale to 64-way processing. Like the initial Raptor machines, the Pteros cluster together four processors, each running at approximately 1GHz and delivering 366 MIPS of processing power when fully activated. Because IBM puts governors on the mainframe engines when they are running z/OS, it is actually scaling the processing capacity on the four-way machine from 26 MIPS to an aggregate of 1,365 MIPS; the company charges based on the MIPS companies activate, not on how many processors are in the box. Customers can designate any of the four processors in the zSeries 890 as a standard processor for supporting z/OS or other mainframe environments or to run Linux within an ILF or to run Java as a zAAP.
IBM also sells two other entry zSeries 800 boxes: a machine with two 80 MIPS mainframe engines, and another made by Hitachi Ltd that has a 40 MIPS general-purpose engine and a 192 MIPS engine designated for Linux.
When configured as an ILF or zAAP, IBM lets the engines in the zSeries 890 run full-out and charges only $125,000 for each engine. In the case of a Linux-only engine, IBM also charges for a z/VM license to partition up that engine so it can support multiple Linux instances. Prior to today’s announcement, that z/VM license cost $45,000, but IBM has dropped the price to $22,500.
That z/VM price cut comes out in conjunction with the announcement today of z/VM V5.1, which will have additional virtualization features above and beyond what it currently has. IBM is also going to preview z/OS V1R6, which will be a requirement to use the zAAP feature.
This article is based on material originally published by ComputerWire
