Power Saving 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 “Power Saving 3.5” Desktop Client” drives.

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

Design Details

Even though it is known that many PCs 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 is reflected in improved notebook PC battery life.

While all drives go through certification testing (CERT) during manufacture, the Power Saving 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 Power Saving version of the Desktop Client 3.5” class drive spins at a lower spin rate, which reduces power draw and (usually) heat generation.

Check Reliability and Costs

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.

	Desktop Client 3.5″
Production Screening?	NO
Rated for 24/7 Use?	NO
Fixed Shaft Spindle?	NO
RV Feed Forward Sensors?	NO
Time Limited Retry Tables?	NO

	Desktop Client 3.5″
Workload Rating	LOW
Firmware Tuning	STANDARD
Performance Capabilities	MEDIUM
Reliability Ratings	LOW
Cost	LOW