This article covers ASUS Intel B365 搭載 socket1151対応 マザーボード PRIME B365M-A 【MicroATX】.

Overview

The ASUS PRIME B365M-A is a microATX motherboard built around the Intel B365 chipset, designed for 8th and 9th generation Intel Core processors on the LGA1151 socket. It supports up to 64GB of DDR4 memory (2666/2400/2133 MHz) and includes a single PCIe 3.0 x16 slot for a graphics card, plus two PCIe 3.0/2.0 x1 slots for additional expansion. A native M.2 slot (PCIe 3.0 x4 and SATA) allows for fast NVMe or SATA SSDs, while six SATA 6Gb/s ports provide ample storage connectivity. Positioned as an entry-level to mid-range solution, the PRIME B365M-A offers a balance of cost and reliability. It lacks the overclocking features of Z-series boards but delivers stable performance for everyday computing, light gaming, and office work. ASUS’s 5X Protection III suite—including overvoltage protection, ESD guards, and a stainless-steel back I/O—ensures long-term durability, making it a solid foundation for budget-minded builders. With a compact 24.4cm x 21.8cm footprint, it fits into most microATX cases, and its sub-$100 price point makes it appealing for those building a lower-cost PC without sacrificing too many features. The board supports Windows 10 64-bit natively, though Windows 11 compatibility may require additional TPM 2.0 hardware.

Compatibility Guide

CPU Socket: LGA1151 (Intel 8th Gen Coffee Lake and 9th Gen Coffee Lake Refresh) Compatible with Core i7-9700K, i5-9400F, i3-9100, and all Pentium/Celeron variants from those generations. Does NOT support 10th Gen (LGA1200) or newer CPUs. Memory: 4x DIMM slots, max 64GB, DDR4-2666/2400/2133 MHz non-ECC unbuffered. Dual-channel configuration works with slots A1 and B1 (or A2 and B2). Expansion Slots: 1x PCIe 3.0 x16 (full x16 electrical), 2x PCIe 3.0/2.0 x1. No support for SLI/CrossFire. Storage: 6x SATA 6Gb/s ports, 1x M.2 slot (PCIe 3.0 x4 & SATA modes). Note: using a SATA M.2 drive may disable one SATA port. USB: 7x USB 3.1 Gen1 (5Gbps) – 4 on rear panel, 3 via headers; 4x USB 2.0 via headers. No USB-C or USB 3.2 Gen2. Power Connectors: 24-pin ATX, 8-pin EPS 12V. Recommended PSU wattage: 450W for typical office builds, 500W+ if pairing with a discrete GPU. Form Factor: microATX (24.4cm x 21.8cm). Fits most microATX cases; not compatible with Mini-ITX cases.

Product Info

Released in early 2019, the ASUS PRIME B365M-A is a motherboard based on the Intel B365 chipset, which sits between the H310 and H370 in Intel’s lineup. It uses the older 22nm process (versus the 14nm of B360) but provides native M.2 support and decent I/O. Price in Japan is around ¥6,700–¥7,000, making it one of the most affordable LGA1151 options. It comes with a 3-year warranty from ASUS. Market tier: entry-level to mid-range. It is not designed for overclocking but offers stable, reliable operation for everyday use.

Best Use Cases

Budget Gaming PC for 1080p Pair this board with a Core i5-9400F and a mid-range GPU like an RTX 3060 or RX 6600. You get solid 1080p performance at a low total cost. Not recommended if you plan to upgrade to a PCIe 4.0 GPU or SSD later. Office / Home Server Build With 6 SATA ports and an M.2 slot, this board is great for a file server or media center. Use a low-power Pentium G5400 and 8-16GB of RAM. Avoid if you need more than 64GB of RAM or ECC memory. Light Content Creation (Photoshop, light video editing) An i7-9700 combined with 32GB of DDR4 allows for smooth editing of 1080p timelines. The single M.2 slot can handle a fast NVMe scratch drive. Not ideal for heavy 4K/8K rendering or tasks that benefit from multi-GPU setups. Who should NOT buy this: Anyone wanting to use a 10th/11th/12th Gen Intel CPU, those who need PCIe 4.0, USB-C, or built-in Wi-Fi, or users planning to overclock their CPU/RAM.

Things to Consider

This motherboard is strictly limited to 8th and 9th Gen Intel CPUs. If you need a newer CPU, you'll have to look at a different socket. Additionally, the chipset does not support Intel Optane Memory or RAID 0/1/5 on the M.2 slot (only software RAID via OS). The lack of USB 3.2 Gen2 means you won't get 10Gbps speeds from external drives. Also, the BIOS chip is relatively small, and the BIOS interface is a basic UEFI with limited overclocking options. If you're building a PC today, consider whether paying a little more for a B460 or B560 board (with LGA1200) might be better for future upgradeability. ## FAQ
Q: Can I use a Core i9-9900K with this board? A: Yes, it is officially supported. However, the VRM design is modest, so sustained all-core loads may cause throttling or higher temperatures. Use a good CPU cooler and ensure adequate case airflow. For maximum performance, a Z390 board is recommended. Q: What is the maximum memory speed supported? A: The official max is DDR4-2666. Installing faster RAM like 3200MHz will downclock to 2666MHz. XMP profiles are not supported for overclocking on the B365 chipset. **Q: Does this board

Product Disclosure (Amazon)

  • Manufacturer: ASUS
  • ASIN: B07Q29M7Z8
  • Note: This article covers a manufacturer-made product based on Amazon listing details.