Motherboards under $100

AM4, mATX, DDR4, 4 Memory slots

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GIGABYTE B550M K AMD AM4 Micro-ATX Motherboard, Supports Ryzen 5000/4000/3000 Series Processors, DDR4, 3+3 Power Phase,

$74.99as of 11/03/2026 23:11 PST - Details

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Spec score8.6

Pros

+Micro-ATX size is compact for smaller cases

+Four RAM slots supporting DDR4 memory

+Two M.2 slots for fast storage

Cons

−No built-in Wi-Fi

Compared with the 8 motherboards on this page

+2 m.2 slots: the most m.2 slots of the 20 here

+4 memory slots: only 1 of 22 here have more memory slots

+1G: only 4 of 30 here have a higher wired lan

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AM4, mATX, DDR4, 1 PCIe x16 slots

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ASUS Prime B550M-A WiFi II AMD Micro ATX DDR4 Motherboard with PCIe 4.0, WiFi 6, ECC Memory, HDMI 2.1, RGB Header

$99.00as of 11/04/2026 12:09 PST - Details

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Spec score8.8

Pros

+Compact microATX form factor

+DDR4 memory with ECC support

+PCIe 4.0 support

+Two M.2 slots for SSD storage

+Wi-Fi 6 built in

Cons

−Single PCIe x16 slot limits graphics card expansion

Compared with the 8 motherboards on this page

+2 m.2 slots: the most m.2 slots of the 20 here

+1 pcie x16 slots: only 2 of 20 here have more pcie x16 slots

+1G: only 4 of 30 here have a higher wired lan

+Wi-Fi 6: only 1 of 5 here have a higher wi-fi

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AM4, mATX, DDR4, 2 Memory slots

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ASRock B550M-HDV Socket AM4 Micro-ATX Motherboard, Supports AMD Ryzen 5000/4000/3000 Series Processors, DDR4 4733+(OC),

$69.99as of 11/04/2026 12:09 PST - Details

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Spec score8.0

Pros

+Micro-ATX form factor fits compact builds

+Supports AMD Ryzen 3000, 4000 and 5000 processors

+Supports DDR4 memory with overclocking up to 4733 MHz

+Includes one M.2 slot for fast storage

+Four SATA ports for additional drives

Cons

−Only two RAM slots limit total memory capacity

Compared with the 8 motherboards on this page

+1G: only 4 of 30 here have a higher wired lan

+4 sata ports: only 2 of 14 here have more sata ports

−1 m.2 slots: 11 of the 20 here have more m.2 slots

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AM4, mATX, DDR4, 128GB

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MSI B550M PRO-VDH WiFi ProSeries Motherboard (AMD Ryzen 5000, AM4, DDR4, PCIe 4.0, SATA 6Gb/s, M.2, USB 3.2 Gen 1,

$89.99as of 11/04/2026 00:18 PST - Details

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Pros

+Supports up to 128GB of memory

+PCIe 4.0 support for newer graphics cards and storage

+Micro-ATX form factor fits smaller builds

+AM4 socket supports Ryzen 5000 series processors

Cons

−Uses older DDR4 memory rather than DDR5

Compared with the 8 motherboards on this page

+128GB maximum memory: only 1 of 17 here have a higher maximum memory

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AM4, DDR4, AMD B550

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ASRock B550M Pro4 Micro ATX Motherboard, AMD AM4 Ryzen 3000-5000, DDR4 4733+ (OC), PCIe 4.0, Dual M.2, HDMI/DP/VGA

$89.99as of 11/04/2026 12:09 PST - Details

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Pros

+Supports 3rd Gen AMD Ryzen and future AMD Ryzen processors

+Uses AM4 socket for a wide range of Ryzen chips

+AMD B550 chipset for AM4 platform builds

+Uses DDR4 memory

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AM4, mATX, DDR4, 2 M.2 slots

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ASUS Prime B550M-K WiFi AM4 mATX Motherboard, DDR4, PCIe 4.0, 2xM.2, WiFi 6 | 2x M.2 Slots, WiFi 6, AMD Ryzen Ready,

$93.98as of 11/04/2026 12:09 PST - Details

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Spec score8.9

Compared with the 8 motherboards on this pagePros

+2 m.2 slots: the most m.2 slots of the 20 here

+1G: only 4 of 30 here have a higher wired lan

+Wi-Fi 6: only 1 of 5 here have a higher wi-fi

How pros and cons are picked (About: Disclaimer)

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AM4, ATX, DDR4, 1 PCIe x16 slots

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ASRock AMD B550 PG Riptide ATX Motherboard Dual Channel DDR4 4933 MHz AM4 Socket 128 GB SATA3 6.0 Gb/s M.2

$89.99as of 11/04/2026 12:09 PST - Details

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Spec score8.3

Pros

+Standard ATX form factor offers room for expansion cards

+Four SATA ports for connecting multiple drives

+Built on the AMD B550 chipset

Cons

−Only one M.2 slot for solid-state storage

−Only one PCIe x16 slot limits expansion options

Compared with the 8 motherboards on this page

+1 pcie x16 slots: only 2 of 20 here have more pcie x16 slots

+4 sata ports: only 2 of 14 here have more sata ports

−1 m.2 slots: 11 of the 20 here have more m.2 slots

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AM4, mATX, DDR4, 4 Memory slots

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MSI PRO B550M-P Motherboard, mATX - Supports AMD Ryzen 5000/5000 G-Series, 4000 G-Series, 3000 G-Series Desktop

$89.99as of 11/04/2026 00:18 PST - Details

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Spec score8.2

Pros

+Compact mATX form factor

+Four RAM slots for DDR4 memory

+AM4 socket supports AMD Ryzen 5000 and older series processors

Cons

−Only 1G LAN for wired networking

−Uses DDR4 memory rather than newer DDR5

−Single M.2 slot limits fast storage expansion

Compared with the 8 motherboards on this page

+4 memory slots: only 1 of 22 here have more memory slots

+1 pcie x16 slots: only 2 of 20 here have more pcie x16 slots

+1G: only 4 of 30 here have a higher wired lan

−1 m.2 slots: 11 of the 20 here have more m.2 slots

How pros and cons are picked (About: Disclaimer)

About this product