SNS Insider’s latest infrastructure-as-a-service report names AWS, Microsoft Azure, Google Cloud, Oracle Cloud, and Rackspace as the top five companies driving cloud innovation. But the inclusion of a managed services provider alongside hyperscale platforms muddies the definition, and for Windows administrators, the real story isn’t who made the list—it’s what the ranking doesn’t tell you about licensing, hybrid costs, and workload compatibility.

A Closer Look at the Top Five

The report, published July 14, 2026, forecasts the global IaaS market to grow from an estimated $120.28 billion in 2025 to $669.97 billion by 2033, a compound annual growth rate of 23.96%. That projection is directional, not a purchasing case. The provider list itself merges public-cloud giants with a company whose core business is managed services.

Amazon Web Services remains the broadest platform by footprint, spanning 123 Availability Zones in 39 geographic regions, with further expansion announced. Microsoft Azure’s strength lies in enterprise integration and hybrid-cloud tools such as Azure Arc, Azure Local, and Defender for Cloud. Google Cloud continues to emphasize Kubernetes, data platforms, and AI, listing 43 regions and 130 zones. Oracle Cloud Infrastructure has carved a niche around enterprise databases and high-performance computing, bolstered by its Cloud@Customer deployment model.

Rackspace Technology, the fifth entrant, primarily helps organizations operate workloads across public, private, and hybrid environments. It is not a hyperscale IaaS vendor in the same sense as the others. That distinction matters when using such lists to shortlist providers for a Windows Server migration.

Azure’s Edge for Windows Workloads—and Its Caveats

For shops running Windows Server, Active Directory, SQL Server, Hyper-V, and Microsoft 365, Azure’s pitch is straightforward: extend existing operational practices rather than rebuild around a different cloud stack. Azure Hybrid Benefit lets you bring on-premises Windows Server and SQL Server licenses with Software Assurance to the cloud, potentially cutting compute costs significantly. Reserved Instances add further discounts for predictable workloads.

That familiarity does not make Azure automatically cheaper or simpler. Licensing is a separate discipline. A Windows Server Datacenter license with active Software Assurance can cover both on-premises hosts and Azure VMs, but only if you correctly track core counts, edition requirements, and the often-overlooked fine print: storage transactions, outbound data egress (the first 100 GB per month is free, after which charges apply), backup retention, and the cost of Azure Monitor or Defender for Cloud add-ons all layer onto the bill. SQL Server licensing introduces its own variables—core-based, per-license, or via the Azure Hybrid Benefit for SQL.

Beyond the Headline: What Windows Shops Should Actually Compare

No industry ranking substitutes for a workload-specific total cost of ownership (TCO) calculation. A Windows Server 2022 VM running a 16-core instance with premium managed disks and 1 TB of outbound traffic will yield different monthly costs on Azure, AWS, and Google Cloud—even before factoring in licensing.

  • Inventory your estate. Document every Windows Server and SQL Server instance: edition, version, core count, current licensing model (OEM, volume license, or subscription), and Software Assurance status.
  • Map dependencies. Note Active Directory domain controllers, DNS, DHCP, certificate services, and legacy applications that may require specific OS versions. Microsoft still supports Windows Server 2012 R2 and newer under Extended Security Updates on Azure, but not all clouds offer the same support lifecycle.
  • Model TCO across at least two providers. Use the Azure Pricing Calculator and the AWS TCO Calculator to build equivalent designs—same vCPUs, RAM, storage type, and networking tier. Then apply licensing: for Azure, factor in Hybrid Benefit; for AWS, compare EC2 Windows instances (license-included) with Dedicated Hosts for BYOL. Google Cloud’s Sole-Tenant Nodes also support Windows BYOL, but the licensing rules differ.
  • Account for migration and exit costs. Data transfer into a cloud is usually free; moving out comes at a per-gigabyte price. On Azure, that’s $0.087 per GB for the first 10 TB. AWS charges $0.09/GB for the first 10 TB. Over a terabyte, these numbers add up. Database licensing, such as moving SQL Server to Managed Instance or Amazon RDS for SQL Server, changes the cost model from IaaS to PaaS, which may be cheaper but limits direct OS access.
  • Evaluate hybrid management. If on-premises infrastructure stays, Azure Arc extends Azure management and governance to any server, including those on AWS or Google Cloud. AWS Outposts and Google Anthos offer analogous but less integrated experiences for Windows admins accustomed to Microsoft tooling.

How We Got Here: The Evolution of Enterprise Cloud

The current IaaS landscape is shaped by a decade of enterprise cloud adoption. In the early 2010s, AWS dominated, and Microsoft responded with Azure in 2010, then doubled down on hybrid with Windows Server 2012 and System Center integration. The shift to per-core licensing with Windows Server 2016 made it more expensive to run Windows on non-Azure clouds if you didn’t bring your own licenses. That licensing complexity persists. Simultaneously, the rise of managed services like Rackspace blurred genre lines: companies now combine hyperscale infrastructure with third-party operations expertise. Analyst firms often lump them together, but for procurement, the distinction is critical.

What to Do Now: A Five-Step Audit

  1. License position snapshot. List all Windows Server Standard and Datacenter cores, SQL Server cores or CAL-based licenses, and verify Software Assurance end dates.
  2. Cloud cost simulation. Build equivalent VMs on Azure and AWS price calculators for at least three representative workloads: a domain controller, a SQL Server database server, and an IIS web front-end. Include outbound traffic estimates and a 30-day backup retention policy.
  3. Benchmark Azure Hybrid Benefit. Calculate your per-core price with and without the benefit. For a 16-core Windows Server Datacenter VM in Azure West US, the monthly compute cost drops from roughly $1,132 (license-included) to $758 (with Hybrid Benefit). AWS’s license-included price for a comparable EC2 instance is about $1,094, but if you BYOL on Dedicated Hosts (which incurs a fixed host charge plus per-core Windows licensing), the math shifts.
  4. Check support for isolated workloads. If legacy apps require bare-metal performance, investigate Azure Dedicated Host, EC2 Dedicated Hosts, or Google’s Sole-Tenant Nodes. For large SQL Server deployments, compare Azure SQL Managed Instance versus Amazon RDS for SQL Server—PaaS can reduce administrative overhead but may require application changes.
  5. Set a time-bound pilot. Migrate one non-critical Windows workload to Azure and one to AWS for 30 days. Monitor performance, network latency from your sites, and actual costs (including hidden charges like NAT gateway data processing fees).

Outlook: AI, Edge, and the Multi-Cloud Default

The IaaS market will accelerate as AI, machine learning, and edge computing push more data into cloud infrastructure. For Windows enterprises, multi-cloud is becoming the norm. Azure Arc and AWS Systems Manager let you manage hybrid estates, but the licensing narrative is shifting: Microsoft’s Azure Hybrid Benefit now allows Windows Server licenses to be used on AWS and Google Cloud under certain conditions (as of the October 2022 licensing update). Watch for Microsoft’s fiscal year 2027 announcements, as changes to license portability could alter the cost advantage of any single cloud. The SNS Insider list matters only as a market snapshot; your own TCO spreadsheets matter far more when real dollars are at stake.