[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: USB Port speeds

Hello Thomas, and thank you for your response and consideration. The format option of -spare=none did help to at least double the performance as you thought. I was able add the parameter to the command in K3B settings as well. However, I was not able to modify any of the selected programs for operation. I did an apt-get for xorriso and cdrskin OK. But the search button in K3B would not offer any other choices than what was provided.
So the performance doubled as you expected but still nowhere near what the DVD performance was able to get. (4500 KB/s vs. 14000 KB/s) The device buffer filled at the beginning and then stayed less than 50% for the rest and it is only a 4 MByte buffer. So my question still remains as to what difference does the media make in the data transfer through the USB port? Unless the drive itself is blocking it.
Would I still have the same problem if directly attached to a SATA port? It sounds like I would.
I also have 6x BD-R media but since they are not erasable I prefer not to just waste them on silly tests to determine what performance I can get. But they are also just the super cheap media. Both are just generic type media.
At this point I am not sure as to what is the best direction, look for another drive or different media. Any thoughts from your past performance / experiences? 

Would drive firmware update help this issue (if available)?

Thanks,
James


On 06/24/2013 04:13 PM, Thomas Schmitt wrote:

Hi,


When I burn a BD-RE at 2x speed it takes forever and
forever with a throughput speed of 2224 KB/s!!

This is most probably a consequence of Defect Management.
The drive writes a buffer full to BD-RE and then checkreads that amount.
If it does not like the quality, then it writes the buffer again.
In case of persisting quality problems, the unwilling pieces of 64 kB
get replaced by blocks from the Spare Area.

2200 kB/s is about 0.5x BD speed. So your drive is not overly happy
with its own write quality. 1.0x = 4.5 MB/s would be normal with
2x nominal speed and good write reults.

Said this, i believe that Defect Management causes more trouble
than it prevents.

K3B ususally uses growisofs for DVD writing, which offers no
means to disable Defect Management on media which are capable
of it. (DVD-RAM does it too.)



Any thoughts or suggestions as to how to get the performance to be at least
as good as the DVD on the BD-RE medium?

You could ask K3B to use xorriso or cdrskin instead of growisofs.
Both have options to disable Defect Management:
   cdrskin ... stream_recording=off ...
   xorriso -as cdrecord ... -stream_recording=off ...

I do not expect this to happen, though.


A better chance for faster writing is to format your BD-RE with
no Spare Area. My drives then leave out checkreading at all.
Since you probably have growisofs installed, try:

   dvd+rw-format -spare=none /dev/sr0

and then use the BD-RE normally with K3B.

Of course you should verify the write success by own means,
when the burn run is done.


Have a nice day :)

Thomas
Reply to: