Windows Server on ARM was announced to much fanfare in March 2017, with servers powered by Qualcomm Centriq 2400 and Cavium ThunderX2 processors co-developed with Microsoft showcased at the OCP US Summit. At the time, Azure vice president Jason Zander told Bloomberg that “this is a significant commitment on behalf of Microsoft. We wouldn’t even bring something to a conference if we didn’t think this was a committed project and something that’s part of our road map.”
That road map has quite clearly hit a dead end—a lack of updates from Microsoft of the subject, and the absence of any partners involved with the project (or companies in the ARM-for-servers market generally) at this year’s Microsoft Inspire conference strongly indicates the initiative is dead. There’s scarcely anyone left to appear, as Anand Chandrasekher, head of Qualcomm’s data center project, left amidst a round of layoffs in May 2018. Marvell’s acquisition of Cavium was finalized in July 2018, with announcements relating to the ThunderX2 stopping at roughly the same time.
SEE: Microsoft Azure: An insider’s guide (free PDF) (TechRepublic)
While Microsoft indicated it produced a port of Windows Server to ARM, it was only displayed at OCP, as well as used internally. Microsoft didn’t indicate that Windows Server would be licensable for on-premises use, though did note that “some Microsoft cloud services already have future deployment plans on ARM servers.” Announcements at the time only indicated that evaluations were performed, but no production workloads appear to have been moved to ARM processors.
What caused the disarmament of the server market?
Qualcomm’s exit from the server market is likely one of divided attention, according to Alan Priestley, vice president analyst at Gartner. “[Qualcomm] didn’t have the appetite to do that, versus everything else that they were doing. There were probably other things happening with Qualcomm… discussions around their licensing model, their attempt to pick up NXP, and Broadcom’s attempt to buy Qualcomm itself,” he said. Marvell’s ThunderX2 is unrelated, from a design standpoint, from ThunderX, as ThunderX2 is based on a design started at Broadcom in 2013 and sold off three years later, as a result of Broadcom’s acquisition by Avago, which had no interest in that business.
Likewise, strong competition from AMD led to the deployment of AMD EPYC processors on Azure, with Microsoft unveiling that for general access in December 2017. AMD EPYC provides a modest cost savings compared to Intel Xeon parts, and drastically reduced engineering costs, as no porting is needed to reach that amount.
Further research into alternative instruction sets in an effort to avoid the “x86 tax” present in the datacenter is likely to persist. “Maybe the world will go with RISC-V instead of ARM to solve this problem,” Priestly said, expressing confidence that RISC-V can scale up to where x86-64 or POWER9 is presently, but that it “requires a fair degree of design justification,” as “it’s not just instruction set that matters. It’s all the goodies that go around the outside of it. All the memory management, virtualization, cache control, all the other stuff that delivers the processor performance,” which ultimately requires investment.
Microsoft’s mixed enthusiasm about alternative ISAs
Microsoft’s track record with alternative ISAs is rather dicey, with Windows 2000 dropping support for Alpha, MIPS, and PowerPC that existed in Windows NT 4.0. Windows XP and Server 2003 briefly supported Intel’s persistent (yet ill-fated) Itanium architecture.
Targeted more toward consumer devices, Windows RT was the first shot at Windows on ARM, which ended poorly, with poor reception of the seven devices that shipped with it. Subsequently, Windows 10 on ARM for “always-connected” PCs using Qualcomm Snapdragon processors were announced in 2017. Compared to the relatively restrictive Windows RT, 32-bit Intel apps can be run seamlessly using an inline emulator, with limitations. While devices shipping with that have been few and far between, Qualcomm is sufficiently enthusiastic about the future of that project to partner with Mozilla to produce a native ARM64 build of Firefox.
For more on Azure, check out “How Linux took over everything, including Microsoft Azure,” “What does Arm’s new N1 architecture mean for Windows servers?,” and TechRepublic’s cheat sheet for Microsoft Azure.
Microsoft did not respond to requests for comment on this article prior to publication.