Installation guide

Appendix B. Fibre Operation
195
Number of AV Stream
RAID controllers are required to have not only the function of processing ordinary data
but also the function of dealing with AV (audio/video) stream data which needs
real-time processing. Since the bus cycle used in RAID controller was designed to
transfer the computer data exactly, it was unsuitable for the transfer of AV stream that
needs a great band widths. They are required to do some setting for the handshaking
during the processing of stream data. This setting can adjust the efficacy of transferring
stream data on an existing RAID controller.
Normally you should not need to modify this value. Default value is 6. You can select
between 6~216.
To decide how to set AV stream playout parameter, you need to check the Number of
Stream, Amount of Read Ahead, and Total Cache Memory during runtime. You can try
to adjust the three numbers to get the best performance as your requirement. Number of
Stream shows the number of stream added to the system, Amount of Read Ahead shows
the amount of Read Ahead data taken from the cache without real disk execution, and
Total Cache Memory shows the total available memory being installed in the RAID
controller.
The following is the rule of optimized setting for the AV Stream Playout application.
Optimize AV Recording
AV recording option is for video recording (no time limit), but if used in normal
operation, performance may be degraded. There are 4 options in this new
feature; Disabled, Mode1, Mode2 and Mode 3. Default value is Disabled. To
decide how to optimize AV stream recording parameter, you need to adjust the
Optimize AV Recording and Write Buffer Threshold during runtime.
Example: Long time video recording (low data rate), such as Surveillance
Optimize HD Edition option: disabled
Optimize AV Recording option: mode3
Write Buffer Threshold: 5%
Read Performance Margin
To reserve more read margin. By increasing Read Performance Margin, user
can get more smoothly on read performance but read speed will be reduced.
Write Performance Margin
To reserve more write margin. By increasing Write Performance Margin, user
can get more smoothly on write performance but write speed will be reduced.