#1 Burning Software

What write speeds should be expected when burning UDF to blu-ray? I'm running a test using the UDFBuildBurn sample in StarBurn 10.5 Tomahawk, burning to a new 25GB BD-R disk. I'm trying to burn approximately 20GB of data (comprised of several small files and one large, 19GB, file). I started the program about 6 hours ago and currently the burn is only 18% of the way through. The drive reported a write speed of 26973KBps. Checking the logs seems to indicate repeated buffer underruns being encountered. (CStarBurn_CdvdBurnerGrabber::TrackAtOnce(): BUFFER UNDERRUN). Any ideas on how to improve the write performance?

1) Actual burning speed would be 1/2 of the reported. B/c Blu-Ray writes and then reads to check integrity.

2) Place your data on hard disk fast enough to have sustained transfer rate HIGHER then burner has.

3) Increase cache size (I have no clue about the one you've used).

Thanks for the reply Anton. I'll have to check on the transfer rate of the hard disk I'm using for the test. Regarding the cache size, I'm using whatever the default size is. The sample passes in STARBURN_CACHE_SIZE_READ_WRITE as the cache size in the StarBurn_CdvdBurnerGrabber_CreaterEx function. What is your software's default value? Is there a typical cache size your developers use in their testing when writing UDF to blu-ray?

Please write simple test: store resulting image not to Blu-Ray, but to ISO image on the hard disk (make sure it's physically other device then the one you use as a source). And calculate "virtual" burning speed. That's the maximum one for you system (b/c write disk writes are cached quite effectively).