Question : Problem: Video & audio stutters when playing back movies

I recently built my own computer for home digital audio work and home office applications. Everything works great, however, I'm having some issues playing back movies and audio. The audio is hanging and skipping whenever the disk activity light comes on. It's driving me nuts. I've tried the same songs & videos on other computers and they play back fine, so I know it's not a problem with the files. Here are my specs

Motherboard - A7S333 (Sis745 Chipset, onboard audio jumper disabled)
CPU-AMD Athlon XP 2200+ 1.8 Ghz
Memory-Samsung 512MB
Hard Drive-Two 40GB Seagate Barracudas (ATA100 7200RPM)
OS-Windows XP Home 2002 (Service Pack 1)
Video Card- Matrox Dual Head G450
Sound Card-Delta 44 (5.10.00.0027 drivers (not digitally signed for XP))


disabled ACPI
disabled onboard audio with mobo jumper and in BIOS
no virus scanning software


Display Properties:
    Power Scheme:
         Always On
         Never turn off monitor
         Never turn off hard disks
    Appearance:
         Windows Classic Style
         No wallpaper
    Display Settings:
         Screen Res 1280 x 1024 (this is the only resolution that is crisp on my monitor)
         Color Quality: medium (16 bit)
    Advanced:
         Video Hardware acceleration:None

System Settings:
    Performance:
         Custom Visual Effects:everything disabled
         Processor Scheduling:Background services
         Virtual Memory: Initial: 1024MB for each drive
    Automatic Updates disabled
    System Restore disabled for all drives
    Device Manager:No Conflicts, No IRQ's shared
         Changed to Standard PC
         Disabled onboard audio
   
Sound & Audio Devices Properties
             
    No sound scheme
    Sound playback: M-Audio Delta 44 Multichannel
    Sound Recording: M-Audio Delta 44 Multichannel
    MIDI Music Playback: Microsoft GS Wavetable SW Synth
    Voice Playback:     M-Audio Delta 44 1/2
    Voice Recording: M-Audio Delta 44 Multichannel

Delta 44 Control Panel
    Disabled "Reset Rate When Idle"
    DMA buffer: experimented with every setting, currently on 384 samples
    Use windows default for MME is not checked


Current Sound, Video, Game Controllers listed:
         Audio Codecs
         Legacy Audio Drivers
         Legacy Video Capture Devices
         M-Audio Delta 44
         Media Control Devices
         Roland PC-300 USB Driver (my MIDI keyboard)
         Roland UM-1 USB Driver
         Video Codecs

    IRQ's
    0     System Timer
    1     PC/AT Enhanced PS/2 Keyboard
    4     Communications Port
    6     Standard floppy disk controller
    8     System CMOS/real time clock    
    12     Microsoft PS/2 Mouse
    13     Numeric data processor
    14     Primary IDE Channel
    15     Secondary IDE Channel

    3     M-Audio Delta 44
    3     SiS 7001 PCI to USB Open Host Controller     5     SiS 7001 PCI to USB Open Host Controller
    10     Realtek Ethernet NIC    
    11     Matrox Millennium G450 DualHead (originally had a ATI Radeon 7500, replacing video card had no effect on my video problems)

You actually read this far! I appreciate any help since I haven't gotten any sleep in weeks!

Answer : Problem: Video & audio stutters when playing back movies

It sure sounds like a sharing thing.  Let's go back to 5thcav's suggestions about DMA.  See WindowsXP will set all of your ATAPI devices (aka your dual Seagate Barracudas) to use PIO mode by default.  This is VERY CPU intensive so you'll want to change it if possible.  To do so, do the following:

1. Open the System Properties dialog and select the Hardware tab.
2. Click the Device Manager button.
3. Expand the entry for IDE/ATAPI controllers.
4. Select the primary channel and click on Properties, and then choose the Advanced Settings tab.
5. For each device listed, change the transfer mode to "DMA if possible." Don't worry - devices that aren't capable of DMA mode will still work just fine.
6. Repeat the process for the secondary channel.

Read this article and see if any of it helps out:

http://www.extremetech.com/article2/0,3973,17085,00.asp

Again... Good Luck!