WD Red SA500 Review: 4TB of SSD Storage for Your NAS

Big bulky SSDs are headed to a NAS near you

WD Red SA500 4TB
(Image: © Tom's Hardware)

Tom's Hardware Verdict

WD’s Red SA500 NAS SSD is a direct response to Seagate’s IronWolf 110, but with its lower cost-per-GB, it is a much better value for those who don’t need extreme write endurance. WD’s Red SA500 is robust enough for most users and is significantly faster than any HDD.


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    High-capacity, up to 4TB

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    Power efficient

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    Robust endurance

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    Competitive performance

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    5-year warranty


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    SSD price-per-GB is high compared to HDD for NAS usage

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Buying and setting up a Network-Attached Storage (NAS) device is a great way to create your own personal cloud for home or office use. With a NAS, you can centralize your data, stream movies to everyone in the house, or even just use it for backup purposes. And then there are the power users that use their NAS for heavier tasks, like running various virtual machines, or in a professional environment to host large 4K and 8K media files and provide concurrent 10GbE connectivity to multiple users.  

It is for the latter who may be interested in one of WD’s latest products, the Red SA500 NAS SSD. It's one of the best SSDs in terms of raw speed, but the robust SATA SSD aims to speed up your NAS so you can focus on work time rather than wasting it waiting for data to transfer from slow but more spacious HDDs. The SA500's low access times paired with high capacities and endurance makes it perfect for caching, or a speedy addition for standard file storage.


Swipe to scroll horizontally
Row 0 - Cell 0 WD Red SA500 500GBWD Red SA500 1TBWD Red SA500 2TBWD Red SA500 4TB
Capacity (User / Raw)500GB / 512GB1,000GB / 1,024GB2,000GB / 2,048GB4,000GB / 4,096GB
Form Factor2.5" 7mm & M.2 22802.5" 7mm & M.2 22802.5" 7mm & M.2 22802.5" 7mm
Interface / ProtocolSATA 6GbpsSATA 6GbpsSATA 6GbpsSATA 6Gbps
ControllerMarvell 88SS1074Marvell 88SS1074Marvell 88SS1074Marvell 88SS1074
MemorySanDisk BiCS3 64L TLCSanDisk BiCS3 64L TLCSanDisk BiCS3 64L TLCSanDisk BiCS3 64L TLC
Sequential Read560 MBps560 MBps560 MBps560 MBps
Sequential Write530 MBps530 MBps530 MBps530 MBps
Random Read95,000 IOPS95,000 IOPS95,000 IOPS95,000 IOPS
Random Write85,000 IOPS85,000 IOPS85,000 IOPS82,000 IOPS
Endurance (TBW)350 TB350 TB1,300 TB2,500 TB
Part Number (2.5")WDS500G1R0AWDS100T1R0AWDS200T1R0AWDS400T1R0A
Part Number (M.2)WDS500G1R0BWDS100T1R0BWDS200T1R0BN/A

WD’s Red SA500 is a SATA 6Gbps SSD that comes in both 2.5” 7mm and M.2 2280 form factors (for more on form factors and other considerations, check out our SSD buying guide). Capacities range from 500GB up to 2TB in both form factors, but the 2.5” model ups the ante a bit with a 4TB model. Pricing is a bit high for a SATA SSD, $0.14 - $0.16 per GB, but the drive comes with relatively high endurance ratings up to 2,500TB and a five-year warranty. In many respects, the SA500 is spec’d similarly to the Samsung 860 EVO.

It supports Trim, S.M.A.R.T. data reporting, and secure erase. The Red SA500 line up is rated for 560/530 MBps of sequential read/write throughput and up to 95,000/85,000 random read/write IOPS. The 4TB model we are reviewing today comes with a slightly lower write IOPS rating, however, of 82,000 IOPS. 

Software and Accessories

WD supports the Red SA500 with the company’s SSD Dashboard, which is a Windows-based application. With it, you can monitor your SSD’s health and performance, update its firmware, secure erase the drive, and more.

The company also offers a free locked down version of Acronis True Image HD 2016 for download that will help you clone your existing data to your new SSD. You can even use it create system images every now and again for back up. 

A Closer Look

The Red SA500’s design is very close to the WD Blue 3D SSDs, even down to the internals. The casing consists of both metal and plastic components and a proven and reliable four-channel Marvell 88SS1074 SATA SSD controller resides inside. The controller supports low-density parity-check (LDPC) code and uses DDR3 DRAM cache. Our 4TB sample comes with 1GB of DRAM for a 1MB:4GB (DRAM:NAND) ratio. The controller interfaces with eight SanDisk BiCS3 64L TLC NAND flash packages and the drive comes from the factory with 9% of its raw capacity over-provisioned.   


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Sean Webster
Storage Reviewer

Sean is a Contributing Editor at Tom’s Hardware US, covering storage hardware.

  • dannyboy3210
    I believe there is an error when listing the model specifications:
    500gb and 1tb both list TBW of 350TB and the spec sheet indicates 350TB & 600TB.
  • Kridian