IBM’s Rumored System i Power6 Server Plans
June 4, 2007 Timothy Prickett Morgan
Now that the first Power6-based server has been launched by IBM–one bearing the System p 570 label and largely based on the existing design of the p5 570 using Power5+ processors–the OS/400 and i5/OS community is naturally beginning to wonder what IBM has in store for them when it comes to Power6 technology. Aside from talking very generally about processors over the past year, IBM has been pretty mum to the press about its plans–for obvious reasons.
But IBM does talk to customers and its software development and reseller partners, and there is usually someone who likes to help out the flagship newsletter in the OS/400 and i5/OS market with some information about what they are hearing out there in the rumor mill. (A fact that we are eternally grateful for, by the way.) I have recently received some information about the future System i Power6 server launch, and because you are all probably trying to figure out your 2008 budgets now–and whether you want to upgrade in 2007 or wait until the new boxes are here–it is my duty to inform you of what people are hearing. The details are a bit sketchy, but they map to other things I have been told and have seen in IBM’s presentations to the System p customer and partner base in recent months. There are some differences, however.
According to one source, IBM is planning for at least three new System i machines, and they fall into the same rough categories the company has been using for years to characterize the “Regatta” Power4 and “Squadron” Power5 families of servers. The Power6 HV8 designation is for a midrange box with four sockets and eight cores in a single chassis; IBM apparently is sometimes pitching this as an entry server, but with all of that performance, you can hardly call it entry. The HV would seem to stand for “high volume” and it also seems clear that such a machine would be, in many ways, more appealing than the four-chassis design of the System p and System i 570 box, which packs from two to 16 cores in four two-socket servers that are linked NUMA-style into a single system image. The other midrange box in the Power6 lineup is designated M/T, and the high-end boxes are designated H. With the Regatta boxes, they were similarly called Regatta-L, Regatta-M, and Regatta-H, roughly corresponding to low-end, midrange, and high-end.
(A side note: I do not know the internal IBM code name for the true Power6 servers, but we had a Navy theme with Power4 and an Air Force theme with the Power5 machines, so I would expect it to be an Army theme. Of course, a Squadron is a Navy term, too, and IBM has preferentially used naval code names in the past. Still, I think to be fair, the Power6 servers should be called Battalion.)
While these are general Power6 server categories that will have both the System i and System p labels slapped on them, one source who contacted me had some more specific information about what the future System i machines would be called and what Power6 processors IBM would use. IBM is apparently going to offer different speeds of Power6 processors in different classes of System i servers, rather than offer two, three, or four different speeds of processors within each server form factor in the System i line. The future 9407-615 server will, according to this source, use a 3.5 GHz Power6 chip, while the 9408-625 will use a faster 4.2 GHz Power6 chip. The documents for the entry System i machines show them having six small form factor disk drives and five PCI-Express peripheral slots. They may also have InfiniBand ports, or they may not. The 9409-655 server will use a 4.7 GHz Power6 chip. These are the same three clock speeds that IBM is offering in the modified System p 570 server right now, which has been given a new processor card and a new memory and I/O subsystem to make use of the Power6 chip. In all three machines, according to this source, each Power6 core will be allocated with six DDR2 main memory slots, giving a single processor card up to a dozen memory slots. With 4 GB DIMMs, that puts main memory at 24 GB per core, but most customers will want to use cheaper 2 GB DIMMs, which IBM is almost certainly going to offer on these “real” Power6 machines. IBM will be offering 667 MHz DDR2 main memory, and might offer slower memory for customers worried about heat. The new Power6 servers will also be equipped with a new service processor based on Big Blue’s own PowerPC 440 embedded processor.
IBM has already confirmed that there will be a variant of the Power6 processor available in a blade server form factor, the first such Power-based blade server that will be able to support OS/400 and i5/OS. It stands to reason that when this blade server is launched, maybe this year or perhaps early next year, that only the latest operating system releases will be supported on the blade. That means i5/OS V5R4 and i6/OS V6R1, if the next release of the System i operating system is indeed called that, and then AIX 5.3 and 6.1 and the latest Linuxes from Red Hat and Novell (that’s RHEL 5 and SLES 10). Given the small business nature of the OS/400 and i5/OS installed base, the desire to have an integrated system, and the willingness to pay a premium for such integration among hardware and software components, this base would seem to have been a natural one to chase with blade form factors. Just as this base was the first to have rack-mounted form factors (a decade before the X86 server market figured it out, by the way). But the excessive heat of the Power4 and Power5 chips prevented IBM from putting these chips on blades, and the blades that IBM did produce with PowerPC 970 and Cell processors cannot run OS/400 and i5/OS, so this was perhaps yet another missed opportunity that could have boosted the sales and profits of the System i business. After all, putting i5/OS-Power and X64-Windows blades side-by-side in a single chassis, with integrated networking and simplified management, would indeed make life easier for a lot of OS/400 and i5/OS shops.
The interesting other story that I have been hearing is that IBM is not sure that it wants to create a 128-core variant of the System i platform. Apparently, the thinking is that with the big jump in per-core performance with the Power6 processor, the radical increase in the usefulness of symmetric multithreading, and the nature of i5/OS workloads today that going beyond a 64-core System i 690 (or whatever it will be called) is not something Big Blue is sure it needs to do right now. Of course, if the System p line has such as 128-core box, as is expected with the Power6 H series of machines, it is a snap for IBM to tweak the box and certify i6/OS on it. Customers willing to shell out many millions of dollars for such a machine won’t have to do a lot of talking to convince IBM to create what will probably be called the System i 695.
As for when the System i Power6 servers will be launched, IBM has been trying to talk everyone out of guessing that they would come in 2007, and the word on the street is that we should expect machines in February 2008. The timing of the announcement–and the nature of the hardware that will be announced–is, of course, subject to change.