Disk I/O questions

Discussion in 'Windows Applications' started by dreamliner77, May 3, 2011.

  1. dreamliner77

    dreamliner77 The Analog Kid

    Messages:
    4,702
    Location:
    Red Sox Nation
    Hey all,

    I just made the jump to running Windows 7 as the only OS on one of machines (2 months ago). I had run 7 as a VM for a while before that. A couple of quick questions:

    Does Win7 see a benefit from moving the pagefile to a separate physical drive? Perris, do you have any insight?

    How much, if any, performance increase do you get from AHCI vs. IDE mode? IIRC, the OS doesn't benefit much from NCQ. Are there other benefits? Also, correct me if I'm wrong, but one needs to do a clean install as AHCI, correct?
     
  2. LordOfLA

    LordOfLA Godlike!

    Messages:
    7,027
    Location:
    Maidenhead, Berkshire, UK
    It depends on the primary workload as to whether you will see any real benefit and then only in low memory situations coupled with memory intensive apps (low memory being defined as under 4GB).

    E.g. Windows on disk 1, page file on first partition right at the start of disk 2, memory intensive app on disk 3. If you have less than 3 disks you'll see no gain at all.

    I'm not aware that AHCI over IDE makes much difference at all in terms of data transfer rates. The usefulness of AHCI comes elsewhere.
     
  3. dreamliner77

    dreamliner77 The Analog Kid

    Messages:
    4,702
    Location:
    Red Sox Nation

    Care to elaborate?
     
  4. LordOfLA

    LordOfLA Godlike!

    Messages:
    7,027
    Location:
    Maidenhead, Berkshire, UK
    If memory serves AHCI just provides things like acoustic management, advanced power saving and other hardware level commands.

    [ame="http://en.wikipedia.org/wiki/Advanced_Host_Controller_Interface"]Advanced Host Controller Interface - Wikipedia, the free encyclopedia[/ame]
     
  5. dreamliner77

    dreamliner77 The Analog Kid

    Messages:
    4,702
    Location:
    Red Sox Nation