Understanding Cloud Host Pricing, Part 1

The pricing schemes of the top cloud infrastructure-as-a-service (IaaS) providers are rather complicated. They cannot be compared directly since their performance characteristics vary. Moreover, the differences in costs of instances, storage, and bandwidth may offset each other. For example, one provider A's storage costs may be greater than provider B but B's instance costs may be greater. Some providers bill for instances by the minute (Azure and Google Computer Engine) whereas others bill by hour (rounded up), such as AWS. Some providers charge for storage by the TB (Azure) whereas others charge by GB/month or sometimes GB/hour (Rackspace). Consequently, what constitutes to the best deal in terms of cloud hosting depends on your specific workloads and storage needs. In this series, we will investigate the various aspects of cloud host pricing from the major providers: Amazon AWS, Microsoft Azure, Google Compute Engine, DigitalOcean, and Rackspace.

To start out, consider the simplest workload: a kind of throwaway micro-instance with vanilla Linux from each of the providers. What is the minimum we can get away with if we do not require load balancing (manual or dynamic) and other services? For this study, we pick the lowest cost zones but do not account for any sustained use or reserved instance discounts because we would like to model the minimum cost where we commit to less than 100% use during the month.

	Azure	DigitalOcean	Rackspace	GCE	AWS EC2
Cost ($/hr)	0.018	0.007	0.032	0.012	0.013
Storage (GB)	20	20	20		None (EBS)
RAM (GB)	0.75	0.5	1	0.60	1

Virtual instance costs

Depending on your workload's latency requirements, the choice of zones may matter and thus impact the actual value of a particular choice of zone for the instance.

	Azure	Rackspace	GCE	AWS
Magnetic	0.000024	0.118	0.04	0.05
SSD	0.07	0.492	0.17	0.10

Block storage costs

Note that AWS's SSD storage is considerably cheaper than GCE's but GCE's magnetic storage is marginally cheaper.