Video : Bus Mastering

Most people don't realize that by default, Windows 95/98 spoon feeds their EIDE hard drive like a baby.  This takes up a ton of CPU time, as much as 50% during capture.  Fortunately, there's a way for the hard disk to feed itself from memory, and to leave the CPU do to more important things.  It's called bus mastering, and it's already supported by Windows 98 and newer versions of Windows 95.  All you have to do is enable it.

Without bus mastering on, as much as 50% of the CPU can be used up in writing to the hard disk.  That increases the chances of dropping frames and limits your framerate, especially if you're using on-the-fly compression like Indeo 5 Quick Compress.  Bus mastering might allow you to reach that extra 1-2fps that you need.

As a bonus, bus mastering can wring an extra 1-2 megabytes per second out of your hard disk as well.

Open Control Panel, and double-click the System icon.  Then choose Device Manager.  Select your hard drive from the tree view.

Click Properties, and then the Settings tab, and you should see the DMA checkbox:

Click OK a few times, and Windows will ask you to reboot.  When Windows restarts, bus mastering should be enabled on your hard drive.  If you don't have the DMA checkbox, your hard drive or IDE controller can't bus master, and you're out of luck.