VidCap: Double Buffering Causes Dropped Frames (99287)

   DEVICE=C:\WINDOWS\SMARTDRV.EXE /DOUBLE_BUFFER
				

MORE INFORMATION

SMARTDrive 4.x provides the capability of caching both read and write operations. If this "double-buffering" is enabled, data is written to the SMARTDrive's buffer first, and from there to the hard disk. For optimal operation, VidCap tries to stream data continuously to the hard disk. If SMARTDrive is double-buffering, VidCap sends data to the buffer, and the data stream is then interrupted as SMARTDrive writes to the hard disk. This can result in either dropped frames throughout the video sequence, or all frames after a certain point to be dropped (depending on the size of SMARTDrive's cache.)

Double-buffering is required for proper Windows operation with some hard disk controllers, but is only suggested as a general performance enhancer with other controllers.

To reduce the number of dropped frames, you can try the following procedures:

1. Comment out the following line from CONFIG.SYS and restart your computer:

         DEVICE=C:\WINDOWS\SMARTDRV.EXE /DOUBLE_BUFFER
   						

   For example, type the following to comment out the above line:

         ;DEVICE=C:\WINDOWS\SMARTDRV.EXE /DOUBLE_BUFFER
   						

2. If Windows fails to operate correctly after this line has been removed (unexpected system hangs, disk read errors, or Windows failing to start), try opening SYSTEM.INI in a text editor such as Notepad and add the following line to the [386enh] section:

         VIRTUALHDIRQ=OFF
   						

3. If Windows still does not operate properly, put the SMARTDrive double-buffering line back into CONFIG.SYS and modify the SMARTDrive line in AUTOEXEC.BAT to read:

         C:\WINDOWS\SMARTDRV.EXE /L
   						

   The "/L" causes SMARTDrive to keep the buffer size small, which results in smoother data streaming to the hard disk.