Amazon S3, Microsoft Azure are top dogs in cloud storage

When it comes to the best-performing cloud service providers (CSPs), the winners are Amazon (s AMZN) S3 and Microsoft Azure (s MSFT), according to a suite of performance and scalability tests performed over the last two years by Nasuni. And, of the 16 large CSPs tested, only six even made the cut at all.

For its “State of Cloud Storage” report, Nasuni — a provider of data continuity services that run on any CSP —  tested everything from API integration (how well the CSP allows integration with outside services), performance (how fast data moved into and out of the cloud); and stability (response-time consistency and frequency/duration of downtime).

For example, Nasuni tested the average write and read speeds for large, medium and small files; how often the CSP experienced outages; and how long downtime lasted.

The six “best in show” cloud services also included AT&T Synaptic Storage as a Service (s T), Nirvanix, Peer1 Hosting, (s PIX) and Rackspace Cloud (s RAX). But Amazon S3 and Microsoft Azure were “clearly the standouts,” according to the report which also stated:

Though Nirvanix was faster than Amazon S3 for large files and Azure was slightly faster for writing files, but no other vendor posted the kind of consistently fast service across all file types as did Amazon S3. Amazon S3 had the fewest outages and best uptime and was the only CSP to post a 0.0 percent error rate in both writing and reading objects. And though Microsoft Azure had a slighty faster average ping time than Amazon S3 (likely because Amazon S3 is much more heavily used than Microsoft Azure), Amazon nevertheless had the lowest variability.

The Nasuni report did not name the CSPs that didn’t make it through the process.  It did note that EMC’s (s EMC) Atmos Online did pass performance, stability and scalability testing, but the service was discontinued earlier this year, replaced by the EMC Atmos platform solution, which lets businesses host their own clouds.

Based on these results and other anecdotal evidence, Microsoft has made big strides with its Azure investment, but Amazon remains the king of cloud based on the sheer amount of work handled.