Large central socket that secures the CPU. Intel uses LGA (pins on socket); AMD uses AM5 (pins on CPU). Socket type determines CPU compatibility.
Typically 2–4 slots for DDR4 or DDR5 memory modules. Dual-channel requires matching sticks in specific slots (check motherboard manual for configuration).
Small ROM chip storing firmware. Runs POST at startup, manages hardware initialization, and hands off to the OS bootloader. Flashable for updates.
x16 slot for GPU (full bandwidth). x1, x4 slots for NIC, audio cards, capture cards. Physical slot size may differ from electrical lanes — check specs.
High-speed slots for NVMe SSDs. Connect directly to CPU PCIe lanes (NVMe) or chipset (SATA). Much faster than 2.5" SATA drives.
Manages communication between CPU and slower peripherals (USB, SATA, lower-speed PCIe). Modern chipsets are a single south-bridge chip.
Connects 2.5" and 3.5" HDDs and SSDs. SATA III tops out at 600 MB/s — significantly slower than NVMe. Still common for mass storage.
Exposed at the back of the case. Contains USB ports, audio jacks, display outputs (if integrated GPU), ethernet, and sometimes PS/2 ports.
| Connector | Purpose |
|---|---|
| 24-pin ATX | Main motherboard power — provides 3.3V, 5V, 12V rails |
| 4/8-pin EPS | Dedicated CPU power — 12V only, near the CPU socket |
| 6/8-pin PCIe | GPU supplemental power from PSU |
| SATA Power | Drives and fans connected to PSU directly |
Full-size standard. 305 × 244mm. Most expansion slots, best airflow. Standard for desktops and workstations.
244 × 244mm. Fewer PCIe slots. Good balance of size and expandability for compact builds.
170 × 170mm. Very compact. One PCIe slot. Used in HTPCs and small form factor builds. Less airflow.