Mainstream 3.5” Desktop Client

Hard drive manufacturers design drives that will perform well for their largest customers, or sets of customers. This is why “classes” of drives exist.

Design Expectations:

The information below is a high-level set of expectations the drive manufacturers have when designing, testing and selling “Mainstream 3.5” Desktop Client” drives.

  • Power On Hours
  • Write / Read Ratio
  • Block Sizes
  • Seek Profile
  • 8 hrs / 5 days(2400 POH)
  • 60/40
  • Random
  • 80% Random / 20% Sequential

Design Details:

Even though it is known that many PC’s actually run for more than 2400 hours per year, the workload is very, very low, compared with industrial uses. This allows the drive makers to put the minimum component quality and robustness into “desktop” drives, and to perform the minimum in testing during manufacture.

For all versions of desktop drives, the firmware tuning is reflective of randomly located blocks of random sized data transfers, and for the 2.5” versions, an emphasis on economy of motion and minimized power usage, which is reflected in improved notebook PC battery life.

While all drives go through certification testing (CERT) during manufacture, the Mainstream 3.5” Desktop Client drives represent the most basic, and least tailored, testing. Subsequently, this class of drives is the lowest quality and reliability available, but also the lowest cost.

The table below is an excerpt from the HDSTOR Drive Comparison Table, which shows features (or lack thereof) of the different classes of drives, as well as relative performance, reliability and cost.

  • Production Screening?
  • Rated for 24/7 Use?
  • Fixed Shaft Spindle?
  • RV Feed Forward Sensors?
  • Time Limited Retry Tables?
  • Desktop Client 3.5″
  • NO
  • NO
  • NO
  • NO
  • NO
  • Workload Rating
  • Firmware Tuning
  • Performance Capabilities
  • Reliability Ratings
  • Cost
  • Desktop Client 3.5″
  • LOW
  • LOW
  • LOW