Hi all. Just received my Biab Ultra Pak preinstalled on 160GB HDD. Checked the drive parameters before running anything off of it. To my great surprise, the partition offset is misaligned. The starting offset is 31K. Because of hard disk architecture, the starting offset on disk partitions should be 1024k (or more as long as it's divisible by 512k).

The problem, in short, is that misaligned disk partitions cause the disk heads to have to work harder resulting in a significant loss of performance. Needless to say, we all want our DAWs to run as efficiently as possible.

Anyone planning on running all or any portion of biab (like real tracks) from the PG Music pre-installed disk would be wise to check the disk's alignment. Misalignment will result in significant performance loss. Partition starting offset can be read in windows explorer >all programs >accessories >system tools >system information.

This is a well known problem with earlier Microsoft operating systems. Microsoft itself recognized the problem and corrected it years ago in subsequent Windows operating systems (like Vista, Windows 7). The newer MS operating systems now default format the partition starting offset at 1024k - properly aligned.

To PG Music - I suspect you folks are installing the biab hard drives - or at least formatting the disks you're installing it on - with the older MS operating systems resulting in the misaligned starting offset I see on my Biab 2011 UltraPak just received. I can't report on the partition offsets of anyone else's Biab HDD, but the one I just received >is mis-aligned<. I was planning on running Biab off of the pre-installed drive. I consider this to be defective and would like to have a replacement with my Biab 2011 UltraPak on a properly aligned drive.


For those out there that just >have< to know, here's a more detailed explanation of the problem:

A disk's architecture is built using 64 sector tracks. In earlier operating systems Microsoft decided to use the first 63 sectors for the disk structure information when creating a partition. Thereafter creating partitions starting at the beginning of sector 64. This is a problem because the next track starts one more sector over at the beginning of sector 65.

Starting the beginning of a partition at sector 64 causes an extra I/O for the drive mechanism while it writes or reads a 4k block of data spread across a barrier of two tracks at the boundary of sectors 64 & 65.

The system uses the first 63 sectors for it's internal information (MBR, disk geometry, etc). Windows then writes data in blocks of 4096 bytes to the next available free sectors - starting at sector 64 - the first 512bytes of data is written to that sector then all writing stops because the mechanism has reached the end of the current track, which then positions itself at the beginning of the next track and continues to write the remaining 3584bytes of the 4096bytes of data in one operation and will continue to do so until the next track boundary. If the mechanism could write the entire data into one track beginning at sector 65 then the drive would complete the task in one operation. With this misalignment flaw writing or reading data that crosses the track boundary takes two operations to accomplish, which now happens at every track boundary until the alignment is fixed.


Cheers (don't shoot me, I'm just the messenger!)