WD Red Pro WD240KFGX in testing: Well-equipped 24TB business NAS

Western Digital's new Red Pro model arrived with 24TB of storage for twice the amount. In this article you can find out what upgrading to enterprise level means in the data sheet and how both models perform in our testing system.

The second article in the 24TB storage space category also comes from Western Digital. The Red Pro for enterprise NAS systems is on par with the WD Gold, 24TB, WD241KRYZ, which we already covered in a previous article. The Red Pro series has received a major innovation quietly and without much fanfare, which we already know similarly from Seagate.

According to the WD Red Pro product brief, as of September 2023 (Link to the manufacturer), the values ​​mentioned in the datasheet have been scaled up to the level of enterprise hard drives. Unlike Seagate, no new names (IronWolf Pro “NE” to “NT”) were introduced to separate the two generations. As is usual for Western Digital, just keep using the old name (for example, WD Red Pro, 18TB, WD181KFGX, link to our article) and now equip the hard drives with an MRW of 550TB and an MTBF of 2.5 million hours and Unlimited hard drive slots. Similar to Seagate, Western Digital's NAS Pro series is now on par with enterprise drives. Except for the optimized firmware for the application in question (NASware for Red-Pro), the Red-Pro, Gold and UltraStar DC-HC5x0 series models no longer differ in the data sheet.

An excellent innovation is the information about non-recoverable errors for each read bit. Western Digital previously specified a value of 1 per 10^14 for the Red Pro series, which could result in a statistically uncorrectable read error on a full read from a net capacity of just under 12TB. Specifying 1 per 10^15 in turn enables a statistically error-free read of just under 120TB, which corresponds to reading the entire Red Pro with 24TB five times. This information is especially important because during RAID recovery, entire hard drives are read at once. If this is not possible without errors from a statistical perspective, this does not speak to data security. The change that has now been made is therefore very welcome.

Otherwise, the WD240KFGX is still an extension of Western Digital's already well-known OptiNAND technology. 10 2.4TB platters spin in the helium-filled hard drive. With 512MB of cache, the 24TB variant is specified at up to 287MB/s according to the manufacturer's website, which matches a maximum transfer rate that is 11MB/s lower than the Gold 24TB, the WD241KRYZ.