This article covers MSI B840M GAMING PLUS WIFI6E Micro-ATX ゲーミングマザーボード MB6805.

Overview

MSI's B840M GAMING PLUS WIFI6E is a Micro-ATX motherboard built around the AMD B840 chipset, designed for Socket AM5 processors including Ryzen 9000, 8000, and 7000 series. It features a white-themed PCB and heatsinks, giving it a clean, minimalist look. With four DDR5 memory slots supporting up to 256GB, a PCIe 4.0 x16 slot, and two M.2 Gen4 x4 slots, it offers solid expansion for a compact board. Positioned as an entry-level to mid-range gaming motherboard, the B840M GAMING PLUS WIFI6E focuses on affordability while retaining modern essentials like DDR5, Wi-Fi 6E, and 2.5GbE LAN. It's an excellent choice for budget-conscious builders who want a reliable platform for current-gen Ryzen CPUs without paying a premium for PCIe 5.0 or extra features they may not need.

Compatibility Guide

CPU socket is AM5, compatible with Ryzen 9000 (Granite Ridge), 8000 (Phoenix), and 7000 (Raphael) series. Memory is DDR5 only – four DIMM slots, up to 256GB, speeds up to 8000MT/s (OC). AMD EXPO supported for easy memory tuning. Expansion slots: one PCIe 4.0 x16 (for GPU) and one PCIe 3.0 x4 (x16 physical). Storage: two M.2 slots (both PCIe 4.0 x4) and four SATA 6Gbps ports. Enough for a fast system drive and mass storage. Power connectors: standard 24-pin ATX and a single 8-pin CPU power. For CPUs like Ryzen 9, a 650W+ PSU is recommended for stable operation. The board is Micro-ATX form factor (244×244mm), so it fits most mATX cases.

Product Info

Released in late 2025, the MSI B840M GAMING PLUS WIFI6E carries a price around ¥21,800. It comes with a 3-year warranty via the official Japanese distributor. Despite being a budget-tier chipset, this board features a white PCB, extended heatsinks with 7 W/mK thermal pads, and an EZ M.2 Shield Frozr for SSD cooling. Market positioning: entry-level to mid-range. It trades PCIe 5.0 and some USB connectivity for a lower price, making it ideal for cost-effective builds where every yen counts.

Best Use Cases

Budget Gaming Build: Pair with a Ryzen 5 7500F or Ryzen 7 8700G and a mid-range GPU like RTX 4060 or RX 7600. The board provides all necessary features for 1080p/1440p gaming without unnecessary extras. White-Themed PC Builders: If you're aiming for a white aesthetic, this board's white PCB and heatsinks are a perfect match. Combine with white RAM, fans, and case for a cohesive look. Compact Micro-ATX Build: The 244×244mm size fits well in mATX cases like the Fractal Design Pop Mini or Cooler Master MasterBox Q300L. It offers good expandability without being oversized. Not for: Users who need PCIe 5.0 for future GPUs or SSDs, or those who want multiple x16 slots for multi-GPU or heavy expansion cards. In those cases, a B650 or X670E board is more appropriate.

Things to Consider

The biggest limitation is the lack of PCIe 5.0. While PCIe 4.0 is still adequate for current GPUs (RTX 40 series, RX 7000 series), next-gen cards may benefit from PCIe 5.0. Additionally, the audio codec is Realtek ALC897 – functional but not high-end. If you're an audiophile, consider a USB DAC. B840 chipset also lacks USB4/Thunderbolt support, so fast external storage is limited to 10Gbps USB-C. The board has only one PCIe x16 slot, so no crossfire/SLI. Overclocking is limited to PBO and memory OC; manual CPU overclocking is not supported. Compared to budget B650 boards, the B840M GAMING PLUS WIFI6E is usually cheaper by ¥3,000–¥5,000, but it cuts corners on PCIe generation and USB speed. For most gamers, the savings are worthwhile. ## FAQ
Q: Can I use Ryzen 7 7800X3D on this board? A: Yes, it's compatible with all Ryzen 7000 series CPUs, including the 7800X3D. You'll get full gaming performance with DDR5 memory. Q: Does this motherboard support overclocking? A: Yes, memory overclocking (EXPO/XMP) and Precision Boost Overdrive (PBO) are supported. However, manual CPU multiplier overclocking is not available on B840 chipset. Q: What PSU wattage do I need? A: For a mid-range build (Ryzen 5 + RTX 4060), a 550W PSU is sufficient. For higher-end Ryzen 7 or Ryzen 9 with a powerful GPU, 650W–750W is recommended for headroom and stability.

Product Disclosure (Amazon)

  • Manufacturer: MSI
  • Seller: Electric UNAGI
  • Fulfilled by: Amazon
  • ASIN: B0FCYDN9QQ
  • Note: This article covers a manufacturer-made product based on Amazon listing details.