This article covers ウエスタンデジタル(Western Digital) WD Red Plus 内蔵 HDD ハードディスク 2TB CMR 3.5インチ SATA 5400rpm キャッシュ128MB NAS メーカー保証3年 WD20EFZX-EC 【国内正規取扱代理店】.

Overview

The WD Red Plus series from Western Digital has long been a go-to internal HDD line for NAS and always-on storage. This review focuses on the WD20EFZX-EC, a 2TB 3.5-inch drive that runs at 5400rpm, packs a 128MB cache, and connects over SATA 6Gb/s. Its defining trait is the use of CMR recording, which keeps write performance predictable compared to SMR drives and makes it well suited to RAID arrays and workloads that rewrite data often. WD Red Plus sits in the entry-to-mid tier of NAS drives, and the 2TB WD20EFZX has been a perennial favorite for first-time NAS builders. With a sustained transfer rate of up to 185MB/s, it is competitive within the 5400rpm HDD class while offering firmware and reliability features targeted at 24/7 operation. The drive carries a three-year warranty, and the combination of accessible pricing and proven dependability explains its long-running popularity. Of course, SSD prices keep falling, but for bulk storage where capacity per yen matters more than access latency, a purpose-built NAS HDD like this one still makes a lot of sense.

Compatibility Guide

The WD20EFZX-EC uses the standard 3.5-inch SATA form factor. Any desktop PC with a free 3.5-inch bay, a NAS with standard SATA drive slots, or a SATA-capable external enclosure will accept it without modification. Power is supplied through a SATA 15-pin connector, so nearly any modern ATX or SFX power supply can handle it. The drive itself draws only a few watts, so no special power headroom is required for a single unit. If you plan to install several drives, count the available SATA power leads and confirm your PSU capacity beforehand. One important caveat: this is a 3.5-inch drive, so it will not physically fit inside a laptop or most mini-PCs. A 3.5-inch external enclosure with its own AC adapter is the workaround in that case.

Product Info

The WD20EFZX-EC is the 2TB model in the WD Red Plus lineup, sold through authorized domestic distributors with a three-year manufacturer warranty. The current street price is around ￥23,840 including tax (as of September 2026), which keeps the entry barrier low for a first NAS build. In terms of market positioning, it is an entry-to-mid NAS drive; the larger 4TB to 8TB siblings cost more per unit, while this 2TB version lets you start a NAS without a large upfront expense. Technically, the drive uses CMR, has a 128MB cache, spins at 5400rpm, and reaches a sustained transfer rate of 185MB/s. Western Digital rates it for a workload of 180TB per year and an MTTF of 1,000,000 hours, which reflects its design intent for continuous operation. It is not the fastest drive in the Red lineup, but the emphasis on stable write behavior and reliability is exactly what NAS owners need.

Best Use Cases

For people building their first NAS, this is an excellent starting point. You can begin with one drive and add another WD Red Plus later. Because it is CMR, rebuilds of RAID 1 or RAID 5 arrays go more smoothly, which gives beginners real peace of mind during the setup process. Photographers and videographers who want long-term storage for finished projects are also good candidates. HDDs still win on cost per terabyte, and a CMR drive is a dependable choice for archives that may sit powered off for months. On the other hand, anyone expecting an HDD to serve as a game library or video-editing cache will be disappointed; sequential and random performance simply cannot match an SSD. Use an SSD for the OS and applications, then point media folders at this drive. It also suits people running a 24/7 file server or DAS. The 5400rpm spindle keeps noise and vibration reasonably low, which makes it acceptable for a NAS placed in a living room or study. Conversely, if you need 4TB or more immediately, or want a single do-everything drive, look at larger capacities or competing NAS lines instead of struggling with 2TB.

Things to Consider

The most obvious limitation is the 5400rpm spindle. The 185MB/s sustained rate is respectable for an HDD, but real-world responsiveness is far below any SATA or NVMe SSD. Keep this drive for backups, media archives, and other sequential workloads rather than putting an OS or games on it. Another point is model confusion with SMR drives. WD Red Plus has historically included some SMR models in certain capacities, so double-check the full part number before buying. The WD20EFZX here is CMR-based, but a quick verification of the "CMR" label and the exact model number will save you from a surprise during RAID rebuilds. Competing NAS-oriented drives in the same class often carry similar warranty terms, so the final choice usually comes down to price and ecosystem preference. Also, 2TB is small by modern standards; if the price gap to a 4TB drive is small, the larger unit may be the better long-term investment for your sto

Product Disclosure (Amazon)

  • Manufacturer: ウエスタンデジタル(Western Digital)
  • ASIN: B08XMF3PT1
  • Note: This article covers a manufacturer-made product based on Amazon listing details.