Question about Set Streaming Command

XinLi at XinLi at
Tue Sep 25 16:12:28 PDT 2001

* From the T10 Reflector (t10 at, posted by:
* XinLi at

Hi, All,

I have a question about the exact meaning/requirements  of command Set
Streaming (opcode == B6) and its implementation.

In MMC 2 Spec, it read" Only zero or one performance extents shall be valid
at any time" (line 8, page 278, MMC version 11a, NCITS 333 T10/1228-D).
The performance extent is defined by the Start LAB and End LBA.  I got
confused with this statement and if it means that only zero or one
performance extent should be there on one disc at any time OR there is only
zero or one valid performance for each performance extent?

If it's the first case, only zero or one performance extent at any time,
the life is much easier, But If it's the later case, there might be this
scenario that there are several performance extents, for example, there are
three extents there and the ranges and speed are as following.

     LBA 10000- 20000,    read 2x , write 4x
     LBA 20001 -- 30000,  read 4x, write 4x,
     LBA 30001 -- 50000,  read 16x, write 8x

All read/write operation within the specified range or  performance extent
should follow the read/write speed defined by the Set Streaming command.

Thank you in advance!

Xin Li
Oak Technology,  Inc.
139 Kifer Court, Sunnyvale, CA 94086
Phone:(408)616-6127  Fax:(408)523-6524
Email: XinLi at

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