A question about "Rip Speed"

Discussion in 'AnyDVD HD (Blu-ray issues)' started by danielhu, May 25, 2008.

  1. danielhu

    danielhu Well-Known Member

    do anyone install 2 blu-ray drives in a computer
    I have 1 GGC-H20L and 1 GGW-H20L in the computer
    every time I rip 2 different Blu-ray movies at the same time
    they both rip at the same speed no matter fast or slow
    do anyone know why? thanks
     
  2. Tyrod01

    Tyrod01 Well-Known Member

    I suspect it's a DMA issue. I had the same issue with DVD drives. I tried to burn an ISO image to multiple DVD burners and found that the overall time was the same as if I had burned them one at a time.

    Even though the LG drives are SATA there is still a primary/secondary relationship sort of like master/slave relationship with IDE drives. Usually, SATA connectors are paired and share DMA. Just make sure that the LG drives are on different SATA channels. I had one SATA motherboard where SATA 1 was paired with SATA 2, and 3 to 4. While the motherboard I have now has SATA 1 paired with SATA 3, and 2 to 4. Consult your MB manual to see if that's the case. I'm thinking that if your LG drives are using different DMA channels and you have multiple processors (dual core or better) then it would almost be like having 2 computers and ripping would only be limited by the speed of the ripping drives.

    Keep in mind that ripping BDs is way slower than DVDs, but I'm sure you already knew that.
     
  3. jbrisbin

    jbrisbin Well-Known Member

    Usually when you encounter a problem like this in an I/O system it represents a bottleneck consisting of single threaded code. That piece of code is single threaded and effectively serializes the operations. One chunk from the first drive, one chunk from the second, one from the first, one from the second...

    For two comparable size discs, this will lead to them always finishing at about the same time.

    If the performance of that code is the limiting factor in the rip, the rip will take twice as long to rip from two drives. If not, it may take the same amount of time as a single drive.

    If you are sufficiently curious to experiment, you can probably locate the bottleneck by disabling or enabling software or changing it to others that perform the same function.

    How are you ripping? Are you using a drag copy from Windows Explorer, CloneCD, ImageBurn. As far a I know you can only get one instance of AnyDVD ripper at a time.

    Rip one disc with one option, the other with one of the others. Did the timing change?

    Try disabling AnyDVD. Does it change?

    Try sending the result to a different physical drive (not partition, different spindle).

    SATA drives (which these are, right?) generally do not suffer from the 'DMA' problems that PATA suffers from (really, PATA suffers from Microsoft's error handling strategy more than anything else).