Description

The Western Digital WDAC22100-32H is a vintage Caviar 22100 series 2.1 GB IDE (PATA) hard drive from the mid-1990s (around 1996–1997 production era, based on date codes like “NOV 96” seen in similar units). It was part of Western Digital’s popular Caviar line for desktop PCs during the Windows 95/early Pentium era, often used as a primary or secondary boot drive in systems with limited capacity needs.

*** Hard drive is tested for good S.M.A.R.T. , no bad sectors and is formatted as a Fat 32 partition.

Key Specifications

• Capacity: 2.1 GB (formatted; raw/unformatted slightly higher, ~2.16 GB in some listings; usable often ~2 GB after OS overhead)
• Interface: IDE / EIDE / PATA (40-pin connector), supports ATA-33 (Ultra DMA/33, burst up to 33 MB/s theoretical; real-world PIO or early UDMA transfers much lower, typically 10–20 MB/s max)
• Form Factor: 3.5-inch standard (full-height, fits desktop bays; dimensions approx. 5.73″ depth × 3.96″ width × 1.02″ height)
• Rotation Speed (Spindle Speed): 5200 RPM (some listings note 5400 RPM variants in the series, but 5200 is most consistently reported for this model)
• Cache/Buffer: 128 KB
• Seek Times:
  • Average seek: ~12 ms (typical for the era; some sources cite sub-17 ms or similar)
• Data Transfer Rate:
  • Internal/media: Not precisely documented, but low by modern standards (~5–10 MB/s sustained)
  • External burst: Up to 33 MB/s (ATA-33 mode)
• Recording Technology: PRML (Partial Response Maximum Likelihood) with Reed-Solomon ECC for error correction; automatic head parking
• Power Connector: Standard 4-pin Molex
• Power Consumption: Low for the time (idle ~3–5 W, active higher; exact figures not widely published)
• Jumper Settings: Standard Western Digital Caviar configuration from the era:
  • Master (MA): Jumper on specific pins (often pins 5–6 or similar; check drive label for diagram)
  • Slave (SL): No jumper or different setting
  • Cable Select (CS): Jumper on CS pins (common for later 1990s setups)
  • Many units support single-drive (master) with no jumper needed, but always verify the physical label or a jumper block diagram
• Geometry (Logical, translated for BIOS): Often reported as 4092 cylinders / 16 heads / 63 sectors per track (or similar LBA-translated values; native CHS may differ due to early IDE translation limits)
• Other Features: Automatic head parking, no onboard jumpers for capacity limiting (unlike some later WD models), reliable for its age but prone to stiction or bearing failure after 25+ years