Performance 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 “Performance 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.

The Performance version of the Desktop Client 3.5” class hard drive spins at a higher spin rate, either 7200 rpm or even 10,000 rpm, although this does increase power draw and heat generation.

Drive Features

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

Solid State Drives offer a compelling choice in this drive class, if you can afford it. Consumer client class SSDs are affordable at smaller capacity points around 100-200GB. They are extremely fast, quiet, cool, and have similar reliability specifications.

Hybrid drives are another interesting choice—the combination of high capacity using hard drive technology and high performance using SSD technology. These drives are also much higher in cost than Mainstream or Power Saving Desktop Client drives, but much lower in cost for the capacity than the SSD option.