Amazon isn't standing pat either. AWS on Wednesday, for example, the ability to set the input/output operations per second (IOPS) in Elastic Block Storage.

There are other differences between Google Compute Engine, which is still in limited preview mode, and Amazon cloud services. AWS has 11 different sizes of compute instances, ranging from small virtual machines with 1.7GB of memory, to extra-large compute clusters with 60.5GB of memory, whereas Google has only four. Google also makes the fiber-optic links between its own data centers available to cloud customers. AWS has a variety of accommodating features in its cloud though, such as the EBS volumes, relational database services, load balancers and others.

The two companies are appealing to different customers, Gaun says. While AWS is targeting technology-reliant businesses that are turning to the cloud to host their websites, databases and storage, Google is focused initially on research and development teams that may have a need for high-performance computing to complete a project, for example. The strategy is seen in the pricing models: AWS offers reserved instance pricing discounts, in which customers agree to use a compute instance for months or even years. Google's cloud is priced by smaller time chunks and therefore aimed at shorter-lived projects.

Gaun says if Google wants to compete in a broader market with Amazon, it will likely have to offer a discounted pricing option for long-term use. That may come in time, Gaun predicts, given that the company's cloud computing offering isn't even generally available yet.

Network World staff writer Brandon Butler covers cloud computing and social collaboration. He can be reached at BButler@nww.com and found on Twitter at @BButlerNWW.