| Rackspace Cloud Servers | Amazon EC2 | |
| Support | Cloud Servers™ is backed by the legendary Fanatical Support you can only get from Rackspace. | To receive 24x7x365 support for Amazon EC2, you pay the greater of $400 per month or 10% (scaling down) of your EC2 costs. |
| Third Party Software Support | The Cloud Servers™ with a managed service level option gives our customers support for a number of third party software. | Amazon does not provide support for third party software even if customers purchase the highest level of support. |
| Admin Level Troubleshooting | If requested by a Cloud Servers™ with a managed service level customer, Rackspace Cloud support techs will log in to a customer’s Cloud Server to help fix a problem. | Amazon Support will not log in to a customer’s EC2 server to help its customers fix a problem. |
| Persistence | One of the most significant differences between Cloud Servers™ and EC2 is the persistence of each virtual server. Cloud Servers™ has access to local, RAID10 disk storage, much like you’d expect in a physical server. | Amazon EC2 instances are transient or ephemeral—if there is a host failure that causes your instance to terminate, all local data on that instance will be lost. Data persistence (not server persistence) can be added with Amazon EBS; however, EBS adds additional cost and complexity. |
| Server Sizes | We provide a wide variety of Cloud Server sizes, starting at 256 MB and going up to 30 GB. Cloud Servers™ can be resized to scale without any reinstallation. | Amazon EC2 Standard Instances start at 1.7 GB, so if your workload requires fewer resources, you are stuck paying for much more than you need. Amazon recently introduced Micro Instances (starting at 613 MB) for customers needing CPU burst capabilities. |
| Hybrid Hosting | Depending on your needs, you can get the best of both worlds with a combination of cloud and dedicated servers with our RackConnect™ solution. | Amazon only offers part of the answer, with only cloud solutions. Amazon VPC is a beta service offering to connect a company’s infrastructure to Amazon’s cloud; however, Amazon does not offer hosting on dedicated/managed servers. |
| CPU Scheduling | Cloud Servers™ has guaranteed minimum CPU power (relative to the size of the Cloud Server), with free bursting when extra capacity is available on the host. | Amazon EC2 instances have a capped CPU. If additional CPU capacity is required, you need to launch another instance. Amazon recently introduced Micro Instances which can be added (at an additional cost) for extra CPU resources. |
| Compute Power | A recent study conducted by an independent third party demonstrated that US-based Cloud Servers™ is, on average, more than two times more powerful than comparable Amazon EC2 servers. | While the pricing of EC2 instances appears to be lower, if it takes more than twice the time to complete a task, the total price to complete a task increases proportionally. |
| Disk I/O | A recent study conducted by an independent third party demonstrated that on average US-based Cloud Servers™ have a higher disk throughput than comparable Amazon EC2 servers. | Amazon has a block storage solution that can show better performance than their built-in ephemeral storage under the right conditions; however, this solution results in additional costs, as both the amount of data stored and transferred are billed for. |
| IP Addresses | Each Cloud Server comes with the simplicity of a dedicated and persistent public IP address (no NAT) with a second, private IP address for free. There is also low latency bandwidth between your Cloud Servers™. Additional public IPs are available upon request and shared IPs can be provided for high availability. | With EC2, the IP configuration is more complex. Each instance gets a non-persistent private IP address NATed to a public IP address. When instances terminate and new ones are launched, a new private IP address is assigned which means you need to plan for changing private IPs. |
| Open Philosophy | In 2010, Rackspace became a founding member of OpenStack, an open-source cloud platform designed to foster the emergence of technology standards and cloud interoperability. | Amazon has not embraced an open-source approach for cloud interoperability. |
Source: http://www.rackspace.com/cloud/cloud_hosting_products/servers/compare/