CiT

A power supply, or PSU, is the component that provides power to everything else inside your PC – and so it’s a crucial. Power supplies include a range of cables to plug into all of the standard components inside a computer. Some PSUs have modular cables, so you only need to fit the cables to you need, resulting in a neater build and better airflow inside the PC.

PSUs are also rated for efficiency, with a more efficient model consuming less power. The ratings go from Bronze to Silver, Gold, Platinum and Titanium.

These PSUs provide 600W, 650W, 700W, or 750W of power, making them ideal for gaming PCs and professional workstations with a single graphics card and some dual-graphics card configurations.

These compact cases support small form factor mini-ITX and micro-ATX motherboards, so take up less room in your home or office. These particular cases include a PSU, do you don't need to buy one separately.

Rackmount PC Cases are designed for server enterprise solutions. They fit into server PC rack mounts. These PC cases are available in specific server sizes namely 1U, 2U, 3U, 4U etc. Advanced features on these cases include handles and specific drive bay slots.
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These tower cases support at least ATX form-factor or larger motherboards so are ideal for building anything from a performance gaming PC to a high spec. home or office computer. They already include a PSU, so you don't need to buy one separately.