When building a computer, one of the initial decisions to be made is with regard to motherboard size and processor compatibility. The motherboard size will determine what size computer enclosure (case) you will use. A larger motherboard can accommodate more expansion options which might be useful for a high-end workstation, server, or gaming computer.

A standard ATX motherboard is 12″ x 9.6″ in size with 9 holes for mounting screws. A Mini-ITX motherboard is 6.7″ x 6.7″ square. It uses four holes for mounting screws. For most people a smaller computer is preferable and can have adequate performance.

A smaller computer can cost less than a larger system because the motherboard, power supply, case and other components are priced lower than their full-size counterparts.

Motherboards

Below are some Mini-ITX motherboards on Amazon. If you scroll down on the corresponding product pages, you will see just below the initial product description there is a heading “Frequently bought together” which will display a CPU and RAM bundle that presumably are compatible. Unfortunately, Amazon does not offer a corresponding “Frequently returned together” list. One presumes that items regularly purchased together will be compatible.

  • ASUS ROG Strix B460-I Gaming (WiFi 6) B460 LGA 1200 (Intel 10th Gen) Mini- ITX SFF Gaming Motherboard (Intel 1Gb LAN, USB 3.2 Gen 2, Addressable Gen2 RGB Header and Aura Sync) [View] Cost: $145
  • GIGABYTE B450 I AORUS PRO Wi-Fi (AMD Ryzen AM4/Mini ITX/M.2 Thermal Guard with Onboard Wi-Fi/HDMI/DP/USB 3.1 Gen 2/Motherboard) [View] Cost: $120
  • GIGABYTE B550I AORUS PRO AX (AM4 AMD/B550/Mini-Itx/Dual M.2/SATA 6Gb/s/USB 3.2 Gen 1/WiFi 6/2.5 GbE LAN/PCIe4.0/Realtek ALC1220-Vb/DisplayPort 1.4/2xHDMI 2.0B/RGB Fusion 2.0/DDR4/Gaming Motherboard) [View] Cost: $180
  • MSI Performance Gaming AMD Ryzen 1st and 2nd Gen AM4 M.2 USB 3 DDR4 HDMI Display Port Mini-ITX Motherboard (B450I GAMING Plus AC) [View] Cost: $119

Power Supplies

The following power supplies are lower wattage power supplies that will probably work well with the mother boards listed above, although no thorough compatibility research has been done for this list. Something to look for in power supplies is an internal fan that is quiet when cooling.

  • Cooler Master Elite 500W Ver.3 – ATX Power Supply Quiet 120mm Fan PCI-E Support [View] Cost: 58
  • Corsair CV Series, CV550, 550 Watt, 80+ Bronze Certified, Fixed Cable Power Supply (CP-9020210-NA) [View] Cost: $60
  • EVGA 110-BQ-0500-K1, 500 Bq, 80+ Bronze 500W, Semi Modular, FDB Fan, 3 Year Warranty, Power Supply [View] Cost: $60
  • EVGA SuperNOVA 550 Ga, 80 Plus Gold 550W, Fully Modular, ECO Mode with Dbb Fan, 10 Year Warranty, Compact 150mm Size, Power Supply 220-GA-0550-X1 [View] Cost: $102
  • EVGA 220-G3-0650-Y1 SuperNOVA 650 G3, 80 Plus Gold 650W, Fully Modular, Eco Mode with New HDB Fan, 7 Year Warranty, Includes Power ON Self Tester, Compact 150mm Size, Power Supply [View] Cost: $145 NOTE: This power supply has removable modular power cords which is a nice feature.
  • Thermaltake Smart 500W 80+ White Certified PSU, Continuous Power with 120mm Ultra Quiet Cooling Fan, ATX 12V V2.3/EPS 12V Active PFC Power Supply PS-SPD-0500NPCWUS-W [View] Cost: $48

Startup Drive

In addition to the motherboard, CPU, RAM, and power supply, you will need a startup drive. Most new motherboards accommodate M.2 NVMe solid state drives. There are a variety of storage capacities available. Speed and reliability will also determine the cost. [View All] An economical choice is the Silicon Power 1TB NVMe M.2 PCIe Gen3x4 2280 TLC R/W up to 3,400/3,000MB/s SSD. [View] $120

Video Card

To save space and money, consider purchasing a CPU with your motherboard that can provide video to the video ports on the motherboard. An example would be the AMD Ryzen 5 3400G 4-core, 8-Thread Unlocked Desktop Processor with Radeon RX Graphics. [View] $140

Mini-ITX Cases

There are a wide variety of enclosures available for Mini-ITX systems. [View All] A few selected cases are listed here.

  • GOLDEN FIELD N-1 Mini ITX Case Computer Case Gaming PC Case Mini Size Desktop Computer Shell Cases [View] Cost: $48
  • NZXT H210 – CA-H210B-W1 – Mini-ITX PC Gaming Case – Front I/O USB Type-C Port – Tempered Glass Side Panel – Cable Management System – Water-Cooling Ready – Radiator Bracket – White/Black [View] Cost: $80
  • Thermaltake Core P3 ATX Tempered Glass Gaming Computer Case Chassis, Open Frame Panoramic Viewing, Black Edition, CA-1G4-00M1WN-06 [View] Cost: $130 Note: Available in gray, white, and black.

Conclusion

In addition to the above components, a keyboard, mouse, and display would be needed.