U.S.-based cloud giants Amazon Web Services (AWS), Microsoft, and Google drove strong growth across the public cloud ecosystem during the first quarter, which itself surged 26% year over year to $126 billion, according to a new report from Synergy Research Group (SRG).

The report found that those three players powered robust 36% growth in the infrastructure-as-a-service (IaaS) and platform-as-a-service (PaaS) public cloud segments, which hit $44 billion in revenues during the quarter.

Amazon, IBM, and Microsoft led a 21% year-over-year increase in managed private cloud revenue during the quarter; Microsoft, Salesforce, and Adobe powered similar growth in enterprise software-as-a-service (SaaS) revenues; and Akamai, Amazon, and Cloudflare headed up a 14% increase in content delivery network (CDN) revenues for the quarter. Those three segments in total generated $54 billion in revenues during the first three months of the year.

SRG had previously reported that Amazon controlled 33% of the global public cloud infrastructure services market at the end of the first quarter, well ahead of Microsoft at 22%, and Google Cloud at 10%.

Those same hyperscale giants also led strong growth in data center infrastructure expansion and capacity. Spending on the former increased 16% year over year during the first quarter, while capacity surged a more robust 18% “from an already massive base, supporting burgeoning cloud services and driving the market for data center hardware,” SRG noted.

The research firm expects public cloud service revenues will double over the next three years.

“Public cloud-related markets are typically growing at rates ranging from 15% to 40% per year, with PaaS and IaaS leading the charge,” SRG Chief Analyst John Dinsdale wrote. “Looking out over the next five years the growth rates will inevitably tail off as these markets become ever-more massive, but we are still forecasting annual growth rates that are generally in the 10% to 30% range.”

SRG also noted that while the ecosystem is posting worldwide growth, the United States “remains a center of gravity.” It found that the U.S. accounted for 44% of cloud service revenues and 51% of hyperscale data center capacity for the quarter. China was the next major market, accounting for 8% of cloud service revenues and 15% of hyperscale data center capacity.