ABI Prism® 7900HT Sequence Detection System ... - OpenWetWare

Defragmenting the
Hard Drive
Upgrading the
Operating System
Software
Applied Biosystems recommends defragmenting the hard drive of the computer
attached to the instrument at least once every week or before fragmentation reaches
10%. As the ABI PRISM 7900HT Sequence Detection System is used and files are
deleted and created, the free space on the computer hard drive eventually is split into
increasingly smaller blocks (called “clusters”). Consequently, as the SDS software
creates new files and extends old ones, the computer cannot store each file in a single
block. Instead, the system will ‘fragment’ the files by scattering their component
pieces across different sectors of the hard drive.
The fragmentation of SDS files decreases the performance of both the SDS software
and the computer operating system. As the hard drive becomes fragmented,
programs take greater time to access files because they must perform multiple seek
operations to access the fragments.
Several commercially available software utilities are available for repairing fragmented
file systems. The software utility defragments broken files by combining their
component pieces at a single location on the hard drive, thereby optimizing system
performance.
Do not upgrade the operating system of the computer connected to the 7900HT
instrument unless instructed to do otherwise by an Applied Biosystems service
engineer. New versions of the Microsoft Windows operating system can be
incompatible with the SDS software and render it and the instrument inoperable.
The Applied Biosystems service engineer maintains the operating system software as
part of planned maintenance visits. During the visit, the engineer will update the
computer operating system as upgrades become available and are validated by
Applied Biosystems.
System Maintenance 7-47