Update : 19th April 2020
Its confirmed that the New Series of WD Red drives ( Ending with EFAX) are shingled and may cause problem during RAID rebuild if mixed with EFRX drives.
Specifications of Western Digital Red NAS Drives are constantly revised and now WD has announced that only the newer EFAX Part numbers will be available on 3 Capacities ( 2,6,8 TB). Now there are rumors that these are SMR drives. If these are SMR ( Shingled Magnetic Recording) drives, then they would be slow with Random writes. Rumor is also that both Seagate and Toshiba are also shipping SMR drives. Its not explained though why would a manufacturer need to ship SMR in lower capacities though.
However this is not yet confirmed that these are SMR drives. In fact the DataSheet of WD shows a higher transfer rate and a higher cache in the new models.
WD20EFRX is replaced by WD20EFAX
WD60EFRX is replaced by WD60EFAX
WD80EFZX is replaced by WD80EFAX.
The newere EFAX drives have better hardware specifications than the older EFRX/EFZX series in the following manners. As its evident, the EFAX series is superior in all the aspects.
- Better Transfer Rate : All the newere series drives have better transfer rates
- Higher Cache : All the newer Drives have 256MB Cache. Higher than earlier
- Slightly heavier with slightly more power consumption
| Model Numbers ( Old Vs New) | Cache ( Old Vs New) | Transfer Rate ( Old vs New) |
| WD20EFRX vs WD20EFAX | 64 MB /256 MB | 147 Mb/s, 180 Mb/s |
| WD60EFRX vs WD60EFAX | 64 MB / 256MB | 175 Mb/s, 180 Mb/s |
| WD80EFZX vs WD80EFAX | 128 MB/256 MB | 178 Mb/s, 198 Mb/s |
