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Mike Diack

Mike Diack Mike Diack

Niner since 2008

  • Mark Russinovich: Inside Windows 7

    Following up Dimebags comments, although as we all can see, Windows I/O handling is problematic, moving onto the more specific issue of the OS hanging while dealing with CDs / DVDs etc (especially those that have physical damage), I'm not convinced that the problem is Windows specific - I'm rather more convinced that most/all drive firmware doesn't handle such media well.

    I've seen similar lockups while trying to read damaged media in OS/2 and Linux. I wonder whether it's not due to the DMA access to the damaged disc "locking the bus" and preventing other activity. I have a strong suspicision that this is the case, since when I've turned DMA off and used the same disc, the lockup doesn't occur (although obviously without DMA, for normal discs, you get very suboptimal performance).

  • Mark Russinovich: Inside Windows 7

    BitCrazed is of course right in a theoretical world, but the reality of Windows systems is that fragmentation and seeking does indeed kill performance on the average system. Its certainly so for me on a quad CPU system, heavy I/O brings the system to its knees responsiveness wise (hangs of c. 30 secs are not unheard of).

    chall3ng3r's entry is interesting, but I think it's much more of a generic issue than even Windows specific. Damaged CD's have the same effect on just about every OS I've tried, including OS/2, Linux, Windows. I rather suspect it's down to the drive's firmware getting stuck in a tight loop and becoming unresponsive and/or locking the bus (?DMA?)

    Can anyone comment?