Azure Cobalt 200: Microsoft's Second In-House ARM CPU for Cloud Servers
Following Microsoft Azure's self-developed ARM processor Cobalt 100, the 50 percent more powerful Cobalt 200 with 132 cores will be available in 2026.
Microsoft Azure Cobalt 200: Server processor with 132 ARM cores.
(Image: Microsoft Azure)
Microsoft's cloud division Azure announces its second custom ARM server processor, the Cobalt 200. It follows the 128-core Cobalt 100 announced in 2023.
Although the Cobalt 200 has only 3 percent more CPU cores than its predecessor (132 instead of 128), it is said to deliver up to 50 percent more performance. To achieve this, Azure uses stronger CPU cores (ARM Neoverse V3 instead of Neoverse N2) and incorporates more cache. Each core has 3 MByte of L2 cache, totaling 396 MByte. Additionally, there is half as much L3 cache.
Azure has TSMC produce the Cobalt 200 chiplets using N3 technology. The processor consists of two chiplets, each with 66 active cores.
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From the ARM Shelf, Plus Extras
To accelerate chip design, Azure already purchased a so-called Neoverse Computing Subsystem (CSS) from ARM for Cobalt 100, meaning not just blueprints for individual cores. The cores of Cobalt 200 are also based on an ARM CSS.
However, Microsoft and Azure emphasize that Cobalt 200 also incorporates proprietary developments. For example, there is RAM encryption to protect memory areas of concurrently running instances against attacks.
(Image:Â Microsoft Azure)
Furthermore, functions of the ARM Confidential Compute Architecture (CCA) are integrated. Like Intel TSX and AMD SNV-SEP, CCA is intended to prevent an attacker with administrator privileges from accessing user data.
Like its predecessor, the Cobalt 200 controls twelve RAM channels. Azure uses it in dual-socket servers, which then have a total of up to 264 CPU cores.
Cobalt 100 instances in the Azure cloud are available with different ratios of CPU cores to RAM capacity. The poorly translated German Azure website for Cobalt 100 instances also refers to the chip as "Kobalt 100". A maximum of instances with 96 CPU cores and 672 GByte RAM can be booked.
Azure plans to offer Cobalt 200 instances in the course of 2026.
ARM Competitors
Other cloud hyper-scalers are also having their own ARM server processors developed. Amazon AWS already uses the fourth version of its Graviton. Google uses the Axion with Neoverse N2.
Oracle Cloud Infrastructure (OCI) uses Altra processors from Ampere Computing, which is now like ARM itself, owned by SoftBank. OCI and SoftBank, in turn, cooperate on the AI project Stargate.
Nvidia also relies on ARM Neoverse in its Grace chips, but always combines them with AI accelerators to form "superchips": Grace Hopper (GH100), Grace Blackwell (GB200, GB300).
To counter the ARM multi-core processors, the x86 CPU manufacturers AMD and Intel have also developed server processors with very many compact (Epyc with Zen 4c/Zen 5c) or E-cores (Xeon 6000E).
(ciw)
