Windows, solid-state disks, and ‘trim’

Fred langa By Fred Langa

It’s a little-known fact that all solid-state disks — all of them — suffer inevitable performance declines over time.

It’s also little known that Windows 7 and Server 2008 are currently the world’s only operating systems to fullyimplement the new trim command that helps forestall this speed decline.


The Achilles’ heel of all solid-state drives

Reader Peter Jackson is frustrated by the diminishing performance of his solid-state disk drive (SSD):
  • “I have a 64GB solid-state hard drive, but no way to restore it to factory-new condition. It has to do with getting the ‘pages’ to read as empty and not just overwritten. It’s important to all SSD users, as the performance degradation is something [all SSDs] eventually suffer from.

    “The few solutions I’ve found are very complex; so far, I haven’t been able to get any of them to work. My SSD seek times degrading from .1 [millisecond] to .4 or .5 may sound silly, but it’s not.”

Performance degradation over time is a known issue with all SSDs, Peter. There are a number of contributing factors — I’ll come back to this in a moment — but some of the worst culprits are standard disk operating commands that were originally designed for use on magnetic, spinning-platter hard drives. SSDs operate differently, and that leads to problems — especially when attempting to reuse previously accessed data blocks, such as the former location of deleted files.

To correct this problem, most current SSDs support a new command called trim. This SSD-specific command does just what you want — it automatically clears out old, overwritten data.

The trim command specification is being made a computing standard by the International Committee for Information Technology Standards, so all OSes will eventually support trim. But for now, only Windows 7 and Server 2008 fully support the trim command. While Linux 2.6.28 is SSD-aware, its partial implementation of trim falls short of Windows’ full support.

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All Windows Secrets articles posted on 2010-01-07:

Fred Langa

About Fred Langa

Fred Langa is senior editor. His LangaList Newsletter merged with Windows Secrets on Nov. 16, 2006. Prior to that, Fred was editor of Byte Magazine (1987 to 1991) and editorial director of CMP Media (1991 to 1996), overseeing Windows Magazine and others.