How Bare-Metal Servers in the Cloud Deliver a Huge Edge in Price/Performance




IT decision makers can drive significant price/performance advantages for their organizations through their choice of Infrastructure as a Service approaches. Cloud services providers basically offer two models for deploying servers for their IaaS customers: Bare-metal servers and/or virtualized servers.

At first glance, using virtualized servers may seem more cost-efficient because the shared infrastructure cost will typically be lower. However, upon close scrutiny, the bare-metal approach can be not only less expensive altogether, but it can also deliver performance advantages that widen the price/performance gap even further. There are several factors driving the price/performance benefits of bare-metal servers:

  • Better overall performance: With a bare-metal server, you can customize the hardware to your unique workload needs. Bare-metal servers do not incur the overhead of a virtualization platform, so the overall speed and responsiveness of the solution will be much better.
  • Lower data transfer costs: Providers of bare-metal dedicated servers will typically offer a much less expensive approach to outbound data transfer. For example, SoftLayer, an IBM company, dedicated servers provide 20 terabytes (TB) per month of free outbound data transfer per server, while some competitive cloud vendors typically offer only up to 5 GB per month free. That’s not a typographical error: It really is terabytes versus gigabytes.
  • Far lower software licensing fees: We will explain this in greater detail below, but the bottom line is that the pricing models for a bare-metal infrastructure can be much more conducive to a low-cost software deployment, particularly in certain environments—and the advantages grow as your deployment grows.

As an example, let’s look at an IBM test study that compared a Web application running on two 4-core bare-metal servers in SoftLayer to the same Web application running on two 8vCP instances in a competitor environment. The SoftLayer bare-metal environment delivered a peak performance of 19,453 requests per second, compared with 7,329 requests per second on the competitor virtual instances. The software costs on SoftLayer bare-metal are half of the cost on the competitor virtual instances due to the difference in number of cores that need licenses. The data transfer cost for SoftLayer in this case was zero, as it falls inside the very large free tier of 20 TB per month, per server.

A major part of the price/performance gap between bare-metal and virtual dedicated servers has to do with the licensing practices of the various vendors. The commodity processors on which most public clouds are built use hyper-threading technology, where one core can simultaneously execute two independent programs. To a virtual machine, these threads appear as two virtual CPUs. So, one physical core is equivalent to two vCPUs.

Many software vendors license their software by core. On an 8-core physical server, IBM or Oracle Enterprise Edition software must be licensed for eight cores. Within a virtualized public cloud, that same 8-core physical server will appear as a 16-vCPU virtual machine. Oracle Enterprise Edition in that environment must be licensed for 16 cores—twice as much. By contrast, IBM software licensed for an 8-core bare-metal server in SoftLayer would require licenses for—you guessed it—8 cores. This can translate into potential for 50% savings in software license fees.

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The cost savings in data transfer are equally compelling. In a bare-metal approach, you can get 20 TB of free data transfer. In well-known virtualized environments you start paying at, for example, 5 gigabytes and then pay for each additional increment based on usage. By the time you’ve reached 20 TB of data transfers, the fees could be a highly unpleasant and unwelcome surprise.

In addition to these price/performance advantages, using bare-metal servers will give you much greater flexibility in your deployment. For example, you are able to configure a server to your exact specifications. In addition, you are able to mix virtual and bare-metal infrastructure together, depending on how you want to approach various workloads. Lastly, you can also create your own virtual private cloud by installing your own virtualization software and pack workloads into that environment in a more cost-efficient manner than general-purpose public clouds.

While bare-metal dedicated servers typically offer a distinct advantage versus virtual servers, there may be times or workloads where you may want to consider virtual servers as an alternative. The ideal solution, therefore, is to work with a cloud provider that offers both bare-metal and virtual approaches. This will give you far more flexibility, while enabling you to take advantage of the benefits of bare-metal servers.