WD recently launched a new part number for 24TB which is based on the newer HC590 platform, and the older 24TB was based on HC580. Let’s see the difference between the two.
Both are 24TB, but they’re built differently
- WUH722424ALE6L4 → Based on HC580
- WUH722624ALE6L4 → Based on HC590
Even though both carry 24TB capacity and are CMR drives, there are a few under-the-hood changes that are interesting.
HC590 is newer and uses 11 platters with Reduced Areal Density
WD’s HC590 platform is the world’s first to pack 11 platters into a standard 3.5" helium-sealed drive. In comparison, the older HC580 uses 10 platters.
Now here’s something counterintuitive — instead of increasing areal density, WD actually reduced it slightly in the HC590. This is likely because the new platters in HC590 are different from those in HC580. But thanks to the two additional recording surfaces, WD still managed to push the capacity up to 26TB.
- HC580 → 10 platters × ~2.4TB each = 24TB
- HC590 → 11 platters × ~2.18TB each = 24TB
So while both are 24TB, HC590 distributes data across more surfaces with slightly lower density.
Cache, MTBF, Transfer Rates, ArmorCache – Nearly Identical
WD continues using CMR (Conventional Magnetic Recording) on both platforms — great for performance and compatibility. You also get OptiNAND and ArmorCache™ for better metadata handling and power loss protection.
Nothing changes except an extra platter
- Both have 512MB cache
- Both rated for 2.5M hours MTBF
- Sustained transfer speeds are close:
- HC580: 298MB/s
- HC590: 302MB/s
- Both have 5 years Limited warranty
- Both have similar MTBF and Workload ratings
Basically, no real-world difference for most applications here.
HC580 would not go obsolete for the sake of 22TB
HC590 is available in both 24TB and 26TB capacities, while HC580 was offered in 22TB and 24TB. Instead of having both series overlap at 24TB, WD has discontinued the HC580 24TB model. However, for 22TB, HC580 will still remain available — since it's the only series that offers a 22TB option.
