Power Systems – Delivering best of breed scalability for SAP HANA

SAP quietly revised a SAP Note last week but it certainly made a loud sound for some.  Version 47 of https://launchpad.support.sap.com/#/notes/2188482 now says that OLTP workloads, such as Suite on HANA or S/4HANA are now supported on IBM Power Systems up to 24TB.  OLAP workloads, like BW HANA may be implemented on IBM Power Systems with up to 16TB for a single scale-up instance.  As noted in https://launchpad.support.sap.com/#/notes/2055470, scale-out BW is supported with up to 16 nodes bringing the maximum supported BW environment to a whopping 256TB.

As impressive as those stats are, it should also be noted that SAP also provided new core-to-memory (CTM) guidance with the 24TB OLTP system sized at 176-cores which results in 140GB/core, up from the previous 113.7GB/core at 16TB.  The 16TB OLAP system, sized at 192-cores, translates to 85.3GB/core, up from the previous 50GB/core for 4-socket and above systems.

By comparison, the maximum supported sizes for Intel Skylake systems are 6TB for OLAP and 12TB for OLTP which correlates to 27.4GB/core OLAP and 54.9GB/core OLTP.  In other words, SAP has published numbers which suggest Power Systems can handle workloads that are  2.7x (OLAP) and 2x (OLAP) the size of the maximum supported Skylake systems.  On the CTM side, this works out to a maximum of 3.1x (OLAP) and 2.6x (OLTP) better performance per core for Power Systems over Skylake.

Full disclosure, these numbers do not represent the highest scaling Intel systems.  In order to find them, you must look at the previous generation of systems.  Some may consider them obsolete, but for customers that must scale beyond 6TB/12TB (OLAP/OLTP) and are unwilling or unable to consider Power Systems, an immediate sunk investment may be their only choice.  (Note to customers in this undesirable predicament, if you really want to get an independent, third party verification of potential obsolesence, ask your favorite leasing companies, not associated or owned by the vendor, what residual value they would assume after 1 year for these systems vs. what they would assume for similar Skylake systems after 1 year.)

The previous “generation” of HPE Superdome, “X”, which as discussed in my last blog post shares 0% technology with Skylake based HPE Superdome “Flex”, was supported up to 8TB/16TB with 384 cores for both OLAP and OLTP, resulting in CTM of 21.3GB/42.7GB/core.  The SGI derived HPE MC990 X, which is the real predecessor to the new “Flex” system, was supported up to 4TB/20TB with 192 cores OLAP with 480 cores.

Strangely, “Flex” is only supported for HANA with 2 nodes or chassis where “MC990 X” was supported with up to 5 nodes.  It has been over 4 months since “Flex” was announced and at announcement date, HPE loudly proclaimed that “Flex” could support 48TB with 8 chassis/32 sockets https://news.hpe.com/hewlett-packard-enterprise-unveils-the-worlds-most-scalable-and-modular-in-memory-computing-platform/.  Since that time, some HPE reps have been telling customers that 32TB support with HANA was imminent.  One has to wonder what the hold up is.  First it took a couple of months just to get 128GB DIMM support. Now, it is taking even longer to get more than 2-node support for HANA.  If I were a potential HPE customer, I would be very curious and asking my rep about these delays (and I would have my BS detector set to high sensitivity).

Customers have now been presented with a stark contrast.  On one side, Power Systems has been on a roll; growing market share in HANA, regular increases in supported memory sizes, the ability to handle the largest single image HANA memory sizes of any vendor, outstanding mainframe derived reliability and radically better flexibility with built in virtualization and support for a maximum of 8 concurrent production HANA instances or 7 production with many dozens of non-prod HANA, application servers, non-HANA DBs and/or a wide variety of other applications supported in a shared pool, all at competitive price points.

On the other hand, Intel based HANA systems seem to be stuck in a rut with decreased maximum memory sizes (admittedly, this may be temporary), anemic increases in CTM, improved RAS but not yet to the league of Power Systems and a very questionable VMware based virtualization support filled with caveats, limitations, overhead and poor, at best, sharing of resources.