More proof that Amazon still leads the IaaS pack, but watch out for those other dogs

It’s not news that Amazon(s amzn) Web Services is the top Infrastructure-as-a-Service (IaaS) provider, but three big non-Amazon players — Microsoft(s msft), Google(s goog) and IBM(s ibm) — are growing like weeds, according to a new Synergy Research Group report.

Using second-quarter revenue data, Synergy found that the non-Amazon big three’s combined cloud revenue is just 63 percent of Amazon’s total. And in a market that grew a robust 47 percent year-over-year, Amazon actually grew its revenue by 52 percent and market share to over 28 percent.

The usual caveat must be applied here: Amazon’s IaaS revenues still remain murky, buried in the infamous “other” category on Amazon’s overall earnings report. And sussing out cloud or IaaS revenue is tricky for other providers, too. The Securities & Exchange Commission is looking into how IBM reports cloud revenue and Big Blue probably won’t be the last legacy IT player to face such queries. But I digress.

In a statement, Synergy Research analyst John Dinsdale said:

“Starting from a much smaller base the big three IT companies actually achieved higher growth rates, but Amazon is doing an impressive job of keeping its grip on market leadership and remains in a league of its own … The real race is to see if any of the chasing pack can establish themselves as a clear number two in the IaaS/PaaS market. While IBM’s acquisition of SoftLayer helped it to leapfrog both Microsoft and Google, the three remain tightly bunched with somewhat similar growth trajectories.”

But one chart is worth a thousand words:

Synergy Research IaaS revenue