Hard drive evolution could hit XP - news item

[IanWilson]

The BBC news site carried this report today about new hard drives that will use 4K sectors instead of 512 byte sectors, which it says could be problematic for anyone wanting to buy a replacement drive for machine running XP.

Ian

[viking33]

The BBC news site carried this report today about new hard drives that will use 4K sectors instead of 512 byte sectors, which it says could be problematic for anyone wanting to buy a replacement drive for machine running XP.

Ian

I wonder just what he is talking about?
The last time I remember using 512 byte sector partitioning was back in the old DOS days.
All of my drives including the XP partition are 4k sectors and have been for years.

[StuartR]

The physical sectors on all hard drives are currently 512 bytes. You can NEVER read or write anything other than a whole number of sectors. If you want to change just one bit you must read the whole sector, modify the bit and then write the sector back to the disk again.

The 4KB units that you refer to are the cluster size. The cluster is the minimum unit of disk space that is allocated by the file system. Larger cluster sizes mean that the bitmap that represents free and used space on the disk can be smaller (1 bit per cluster). If the cluster size is 4KB then a file that is only 5 bytes long will have 4KB of disk space allocated to it. The file system won't have to read and write the entire 4K cluster when it reads and writes the disk, it will only access the sectors that it needs to.

4KB is the default NTFS cluster size for volumes up to 16TB - see Microsoft Knowledge Base article 140365 for more information.

[viking33]

The physical sectors on all hard drives are currently 512 bytes. You can NEVER read or write anything other than a whole number of sectors. If you want to change just one bit you must read the whole sector, modify the bit and then write the sector back to the disk again.

The 4KB units that you refer to are the cluster size. The cluster is the minimum unit of disk space that is allocated by the file system. Larger cluster sizes mean that the bitmap that represents free and used space on the disk can be smaller (1 bit per cluster). If the cluster size is 4KB then a file that is only 5 bytes long will have 4KB of disk space allocated to it. The file system won't have to read and write the entire 4K cluster when it reads and writes the disk, it will only access the sectors that it needs to.

4KB is the default NTFS cluster size for volumes up to 16TB - see Microsoft Knowledge Base article 140365 for more information.

OK, makes sense. I guess I just quickly scan\read that article and confused sectors and clusters.

[ChrisGreaves]

... and confused sectors and clusters.

This problem still has not surfaced with 80-column punched cards ...