Gain values used by a variable gain amplifier (VGA) to read servo marks of a heat-assisted recording medium are measured. Sector-specific, repeatable gain values that indicate an expected VGA gain at a desired clearance are determined based on the measured gain values. The sector-specific, repeatable gain values are used as input to a closed-loop clearance controller together with measured values of servo VGA gain while writing data to the recording medium.

Disclosed herein are suspension assembly structures for data storage devices that include physical or virtual crossovers of the pairs of differential signal traces to improve immunity to crosstalk and other interference. In an embodiment, the suspension assembly structure comprises a first trace for carrying a first component of a current to a differential transducer on a slider, a second trace for carrying a second component of the current to the differential transducer on the slider, and third and fourth traces for providing a differential write current to a writer of the data storage device, wherein the first trace physically crosses over the second trace at a first distance from a tail of the suspension assembly structure.

A baseline performance of a disk drive is found based on a media speed and a bit aspect ratio of the drive. A parallelism architecture is chosen for the disk drive based on an end-use application of the drive. The parallelism architecture includes two heads capable of simultaneously accessing one or more disks of the disk drive. An increased performance of the disk drive is determined due to the parallelism architecture, and at least one of the media speed and bit aspect ratio are reduced such that a final drive performance with the parallelism architecture satisfies the baseline performance, the baseline performance being less than the increased performance. The reduction of the media speed and/or bit aspect ratio increases another capability of the drive over that of the equivalent drive.

A baseline performance of a disk drive is found based on a media speed and a bit aspect ratio of the drive. A parallelism architecture is chosen for the disk drive based on an end-use application of the drive. The parallelism architecture includes two heads capable of simultaneously accessing one or more disks of the disk drive. An increased performance of the disk drive is determined due to the parallelism architecture, and at least one of the media speed and bit aspect ratio are reduced such that a final drive performance with the parallelism architecture satisfies the baseline performance, the baseline performance being less than the increased performance. The reduction of the media speed and/or bit aspect ratio increases another capability of the drive over that of the equivalent drive.

According to one embodiment, a magnetic disk device which supplies, at the time of startup of data write or startup of data read, electric power higher than steady electric power used to make, in advance, spacing between a magnetic disk and a magnetic head become saturated at a target value to a heater of the magnetic head for a specified time and, after an elapse of the specified time, gradually reduces the electric power to be supplied to the heater of the magnetic head to the steady electric power.

A media player may include a media reader to read media content from a recording medium inserted into the media reader. The media player may also include a media analysis component to identify one or more valid portions of the recording medium containing media content and one or more invalid portions of the recording medium without media content. In one embodiment, the media player includes an archival component to store the media content from the one or more valid portions in a storage medium and a playback component to play back the one or more valid portions of the media content from the storage medium concurrently with the identification of the one or more valid portions by the media analysis component and the storage of the media content by the archival component.

Gain values used by a variable gain amplifier (VGA) to read servo marks of a heat-assisted recording medium are measured. Sector-specific, repeatable gain values that indicate an expected VGA gain at a desired clearance are determined based on the measured gain values. The sector-specific, repeatable gain values are used as input to a closed-loop clearance controller together with measured values of servo VGA gain while writing data to the recording medium.

A method includes moving a heat-assisted magnetic recording head relative to a magnetic recording medium comprising a plurality of tracks, the head comprising a reader and a writer including a near-field transducer (NFT) optically coupled to a laser diode, the writer comprising a center which is laterally offset relative to a center of the reader to define a writer-reader offset (WRO) therebetween. Patterns are written to a particular track at a plurality of laser diode current levels. The patterns are read and a WRO value is calculated at a peak amplitude position for each of the laser diode current levels. A slope of the WRO values is determined with the laser current diode levels. A health condition of the NFT is determined by determining if the slope is greater than a predetermined threshold indicative of non-uniform activation across the NFT.

A method includes moving a heat-assisted magnetic recording head relative to a magnetic recording medium comprising a plurality of tracks, the head comprising a reader and a writer including a near-field transducer (NFT) optically coupled to a laser diode, the writer comprising a center which is laterally offset relative to a center of the reader to define a writer-reader offset (WRO) therebetween. Patterns are written to a particular track at a plurality of laser diode current levels. The patterns are read and a WRO value is calculated at a peak amplitude position for each of the laser diode current levels. A slope of the WRO values is determined with the laser current diode levels. A health condition of the NFT is determined by determining if the slope is greater than a predetermined threshold indicative of non-uniform activation across the NFT.

In a storage device, data is written to tracks on a storage medium. Data for each track includes a preamble. The preamble in any current track is orthogonal to the preamble in any track adjacent to the current track. A first read head is positioned over the current track and off-center toward a first adjacent track on a first side of the current track to detect first signals from among the current track, the first adjacent track, and a second adjacent track on a second side of the current track. A second read head is positioned over the current track and off-center relative to the current track toward the second adjacent track to detect second signals from among the current track, the first adjacent track, and the second adjacent track. Analyzing the first and second signals determines an amount by which the read heads are off-track from the current track.