Western Digital makes a family of network-attached storage (NAS) drives that can be used in enclosures with up to 24 bays. They are separated into three ranges: WD Red, WD Red Plus, and WD Red Pro. Depending on how much you’re willing to spend and what features you need, I’m going to run you through all the differences.
WD Red, WD Red Plus, or WD Red Pro?
Western Digital separates its best NAS drives into three ranges. The first is Western Digital Red. This is the most basic family of drives with a capacity range of between 2TB and 6TB. They support up to 8 bays only and make use of SMR for HDD writing technology, which is subpar against CMR in Plus and Pro drives.
Western Digital Red Plus drives take things to the next stage with CMR technology and larger capacities. Speeds of the motor also increase as you move up the capacity chart, resulting in faster transfer speeds. Workload and mean time between failure (MTBF) are also identical to the baseline Red range.
Lastly, we’re got Western Digital Red Pro, which supports NAS enclosures with up to 24 bays and tops out at 18TB each. Motor speeds are all 7,200RPM. Western Digital also bumps up to workload to 300TB per year, as well as the limited warranty to five years.
Specs | WD Red | WD Red Plus | WD Red Pro |
---|---|---|---|
Technology | SMR | CMR | CMR |
Bays | 1-8 | 1-8 | 1-24 |
Capacity | 2-6TB | 1-14TB | 2-18TB |
Speed | 5,400 RPM | 5,400 RPM (1-4TB) 5,640 RPM (6-8TB) 7,200 RPM (8-14TB) | 7,200 RPM |
Cache | 256MB | 16MB (1TB) 64MB (1TB) 128MB (2-8TB) 256MB (8-12TB) 512MB (14TB) | 64MB (2TB) 256MB (4-12TB) 512MB (14-22TB) |
Workload | 180TB/yr | 180TB/yr | 300TB/yr |
MTBF | 1 million | 1 million | 1 million |
Warranty | 3 years | 3 years | 5 years |
Price | From $63 | From $50 | From $70 |
What are CRM and SMR?
Shingled magnetic recording (SMR) and conventional magnetic recording (CMR) are two methods of writing data to the disks spinning within mechanical hard drives. The former is a cheaper way of doing it and can also be found in larger drives. A drawback of this technology is it can’t really hold up with large amounts of data being written regularly.
CMR drives are able to maintain higher transfer speeds. They use more energy than SMR, but you likely won’t notice a difference with the best NAS. There’s no wrong choice here as both technologies will be great for use in a NAS. Unless you’re moving lots of data, CMR and SMR will perform largely the same.

Western Digital Red
The baseline of NAS drives from Western Digital ranges between 2TB and 6TB. You won’t be able to use them in more than 8 bays and they’re limited in speed, cache, and other features.

Western Digital Red Plus
The next set of drives is the Western Digital Red Plus. These range between 1TB and 14TB and also can only be used in NAS enclosures with up to 8 bays. Generally, they’re a little faster than Red drives.

Western Digital Red Pro
Finally, we have the Western Digital Red Pro. This family of drives ranges between 2TB and 22TB and it’s the fastest of the bunch. We’re also talking about higher workload rates and other handy NAS features.