Emulation or virtualization: What’s the difference?

By Lance Boley, Product and Solutions Evangelist, Dell

Emulation and virtualization carry many similarities, yet they have distinct operational differences. If you’re looking to access an older operating system within a newer architecture, emulation would be your preferred route. Conversely, virtualized systems act independent of the underlying hardware. We’ll look to separate these often confused terms, and describe what each of them mean for business IT operations.

What’s the difference?

Emulation, in short, involves making one system imitate another. For example, if a piece of software runs on system A and not on system B, we make system B “emulate” the working of system A. The software then runs on an emulation of system A.

In this same example, virtualization would involve taking system A and splitting it into two servers, B and C. Both of these “virtual” servers are independent software containers, having their own access to software based resources – CPU, RAM, storage and networking – and can be rebooted independently. They behave exactly like real hardware, and an application or another computer would not be able to tell the difference.

Each of these technologies have their own uses, benefits and shortcomings.


In our emulation example, software fills in for hardware – creating an environment that behaves in a hardware-like manner. This takes a toll on the processor by allocating cycles to the emulation process – cycles that would instead be utilized executing calculations. Thus, a large part of the CPU muscle is expended in creating this environment.

Interestingly enough, you can run a virtual server in an emulated environment. So, if emulation is such a waste of resources, why consider it?

Emulation can be effectively utilized in the following scenarios:

  • Running an operating system meant for other hardware (e.g., Mac software on a PC; console-based games on a computer)
  • Running software meant for another operating system (running Mac-specific software on a PC and vice versa)
  • Running legacy software after comparable hardware become obsolete

Emulation is also useful when designing software for multiple systems. The coding can be done on a single machine, and the application can be run in emulations of multiple operating systems, all running simultaneously in their own windows.


In our virtualization example, we can safely say that it utilizes computing resources in an efficient, functional manner – independent of their physical location or layout. A fast machine with ample RAM and sufficient storage can be split into multiple servers, each with a pool of resources. That single machine, ordinarily deployed as a single server, could then host a company’s web and email server. Computing resources that were previously underutilized can now be used to full potential. This can help drastically cut down costs.

While emulated environments require a software bridge to interact with the hardware, virtualization accesses hardware directly. However, despite being the overall faster option, virtualization is limited to running software that was already capable of running on the underlying hardware. The clearest benefits of virtualization include:

  • Wide compatibility with existing x86 CPU architecture
  • Ability to appear as physical devices to all hardware and software
  • Self-contained in each instance

Between emulation and virtualization, your business can perform most virtual systems functions. While both services sound alike, it all revolves around how you utilize the software. If you want the software to get out of the way, virtualization allows guest code to run directly on the CPU. Conversely, emulators will run the guest code themselves, saving the CPU for other tasks.

About the Author: Power More