# Introduction

**XR hardware** are the physical, hardware components used to access XR content. Contemporary XR hardware typically consists of a set of interconnected off-the-shelf hardware and software components, which we will refer to as an [XR system](https://pimkb.gitbook.io/pimkb/preserving-xr-hardware/head-mounted-display). 

## Assessing XR Hardware

To start developing a preservation plan for XR hardware, begin by assessing characteristics of the hardware that the experience/content you wish to preserve depends on. Consider the following prompts:

* What kind of **computer system** is needed to run the software?
  * How flexible is the specification of the hardware? 
  * Is a **dedicated** [**GPU**](#user-content-fn-1)[^1] required? If so, does it require one with a specific feature set? 
* What kind of **interactivity** is supported (refer back to [Initial Assessment](https://pimkb.gitbook.io/pimkb/getting-started/initial-assessment))? What kind of specialised XR hardware is needed to support this? 
  * Does the experience require the use of a **controller** or other **human interface device (HID)**? 
  * If yes to above, can this be fulfilled by a generic piece of hardware or is a specific or custom-made device required? 
* Are there any technical or conceptual reasons that [**specific XR hardware**](https://pimkb.gitbook.io/pimkb/preserving-xr-hardware/head-mounted-display) (e.g. [HMD](https://pimkb.gitbook.io/pimkb/preserving-xr-hardware/head-mounted-display)) is needed to access the XR content? 
  * Dependency relationships with specific hardware can be baked into software when it is created (e.g. by using certain manufacturer-specific plugins).
  * A creator might prefer certain hardware for its characteristics (e.g. technical, visual, conceptual).
* **How many users** are supported simultaneously? e.g. single or multiple stations providing access, discrete or shared experience.
* Does the software require **internet access**? If so, what for and does this need to be maintained?
* Does the experience involve **sound**? How is this played back? 
  * How is **sound** played back? Is this via the HMD or is additional hardware required to support this? e.g. audio interface, speakers, headphones.
  * Is [**spatial audio**](https://pimkb.gitbook.io/pimkb/preserving-360-video/spatial-audio) utilised and if so how is it played back? e.g. via positional speakers or head-related transfer function (HRTF) through an [HMD](https://pimkb.gitbook.io/pimkb/preserving-xr-hardware/head-mounted-display) or headphones. 
  * Is **subtitling or captioning** used, or might they be needed? 

[^1]: **G**raphics **P**rocessing **U**nit, also known as a graphics card or video card.