It's A Digital Disease!

The original post: /r/datahoarder by /u/PricePerGig on 2025-03-28 20:59:35.

I'll be putting this on the website for future ref, but just so you guys know what's what at pricepergig.com for the CMR tags right now we have Western Digital and Seagate completed as per spec sheets and known model numbers.

PLEASE do correct any errors if you know, but this is as discussed earlier in the week and what was concluded, so fingers crossed, all is well.

Western Digital Drive Classifications

Western Digital's documentation is less consistent than Seagate's, but I've developed rules based on their product documentation and community research:

• WD Red Plus and Red Pro: All models use CMR
• WD Red (standard): Current models (except 2.5" drives) use SMR, although some older models were CMR. Using the EFAX suffix to identify SMR drives I tag them as SMR, and use the EFRX suffix to identify CMR drives and tag them as CMR. If I can't identify the model number I won't tag the drive. We can collectively blame Western Digital for this mess.
• WD Gold, Purple, Purple Pro: All models use CMR
• WD Blue: Varies by model - 2.5" drives typically use SMR; 3.5" 8TB models use CMR - if I'm unsure I don't tag the drive.
• WD_BLACK: All desktop (3.5") models use CMR
• Ultrastar DC HC620: All models use host-managed SMR (HM-SMR)
• Ultrastar DC HC550/560/570: All models use CMR (some with ePMR/EAMR technology)

Drives I Don't Tag (Uncertain Classifications)

I prioritise accuracy over completeness, so some drives remain untagged when I cannot confidently determine their recording technology:

• Older drive models with limited documentation
• Drives with inconsistent information across sources
• Enterprise drives with specialised configurations
• Certain Western Digital models:
  • WD Black 2.5" (various technologies based on capacity)
  • WD Blue 3.5" smaller than 2TB
  • Some Ultrastar models without clear documentation (DC HC510, HC520)
  • Models with conflicting information in different sources

Technical Implementation Details

For those interested in the technical details, here's how my tagging system works:

1. I first normalise drive brand names (e.g., "WD" becomes "Western Digital")
2. I identify the product line from the product name (e.g., "BarraCuda Pro", "WD Red Plus")
3. I extract the form factor (2.5" or 3.5") and capacity
4. I check for explicit technology mentions in the product name
5. I apply brand-specific rules based on product line, form factor, and capacity
6. I apply model number specific rules for certain drive models
7. I regularly update my rule set as new information becomes available

This multi-layered approach helps me provide the most accurate information possible while acknowledging the limitations of manufacturer documentation.

Western Digital Tagging Logic

For Western Digital drives, the tagging system follows these key rules:

• Checks model numbers first (e.g., EFAX suffix typically indicates SMR for WD Red drives)
• Applies product line rules (e.g., all WD Red Plus and Pro drives are CMR)
• Considers form factor and capacity combinations
• Uses special rules for Ultrastar enterprise drives

For example, a simplified decision flow might look like:

Resources and References

For those wanting to learn more about drive recording technologies, I recommend:

• Seagate's official CMR/SMR list
• Western Digital's recording technology guide