This week Intel announced its new Xeon E7 v4 processor, which takes x86_64 processor scale to another level: a single CPU socket now gives you 24 cores and access to 3TiB of RAM. That means a medium-sized server of 8 sockets can now give you access to 192 cores and 24TiB RAM. The upshot of this is that is you actually want to access all of that RAM with a supported operating system, SUSE Enterprise Linux is your only choice.
The new architecture also raises the limit for CPU sockets in a box to 64 – which means that you could max out this system in a standard kind of configuration at 1,536 cores. Again, SUSE Enterprise Linux is the only OS to support this degree of scalability for this kind of processor.
I wrote about this just a few weeks ago in the context of the HPE Integrity Superdome X, which still only has published benchmarks running SUSE Linux Enterprise Server. It's interesting to see that all of the numbers have doubles (yet again) in such a short time.
Of course, SGI has been doing this degree of scaling with NUMA systems for a while, which is why SUSE Enterprise Linux is known to scale to 8,192 CPU cores and 64TiB RAM (they couldn't fit in any more memory): it's a little frightening to consider what they might end up doing with these new CPU's – at the very least 128TiB RAM will be near on the horizon.
So when the processor hardware manufacturers can still drop a doubling of capacity on us, it's worthwhile taking a note of whether your software can deal with it....
Unlike other material herein, this is an unashamedly partisan post. It's here's to collect together mostly links, for reference.
In December 2014, HP (now HPE) announced the successor to its long line of proprietary enterprise class computer systems: the Integrity Superdome X.
What was particularly interesting about this announcement is that the focus was not just on the Intel Xeon processor, or the scalability of the machine to 16 CPU's and 24 TB of RAM, but what Jeff Kyle, director of product management for mission-critical systems at HP said was most important: "It's all about the software," Kyle told eWEEK.
Superdome X was the first flagship system from HP to not ship with HPUX. Instead its launch OS was Linux. SUSE Linux.
Why? Well SUSE Linux was the launch OS for Superdome X. And yes, that article mentions our old friends from Raleigh, but the fact remains that at launch time, the only benchmarks provided by HP were those with SUSE Linux.
So how about now, 18 months later? Well according to the SPEC website, as of today ALL of the SpecJBB and SpecCPU benchmarks published by HPE for Superdome X use SUSE Linux Enterprise Server:
At the very least, this means that to handle a fully-loaded Superdome X with 24TB of RAM you must use SUSE Linux or risk falling into the "experimental" or at best "unsupported" category. And risk isn't really want you want when running a mission-critical system.
In particular, SUSE Enterprise Linux has actually tested scalability on other systems to 8192 CPU cores and 64TB RAM (no-one could supply a machine with more RAM; the CPU count was qualified after that article was written). SUSE's numbers are therefore not theoretical when it comes to the demands of Superdome X: there is no risk that scaling will not follow the expected path. This difference is likely to continue as well: both HPE and Intel spend a lot of effort developing code for the Linux to improve scalability, etc, and this is sent “upstream” to the latest kernel versions. This means that you would normally expect the most recent kernel version would have the best performance, due to HPE & Intel contributions. Typically SUSE leads its competitor in implementing the latest kernel features whilst maintaining application and kernel binary compatibility between major kernel releases (e.g. from SLES 11SP1 with 2.6 kernel to SLES 11 SP2 with 3.0 kernel). Given this background it should not be surprising for SUSE to continue to make similar advances in its current SLES 12 major release. Historically Red Hat has not changed major kernel releases: RHEL 5 & 6 were kernel level 2.6, with 3.10 introduced only in 2014 with RHEL 7.
In other words: as HPE continues to contribute performance & other features to Linux for all of its server platforms, these are most likely to appear (with full global enterprise-class support) on SUSE Enterprise Linux long before they are available on RHEL.
