Thanks. I'm assuming these calls will work for sequential access files (as well as random block access).
That sounds like BASIC file modes rather than something done at the OS level
So the problem is with the programmer's implementation of ATI's MMC video recording software, not the design of Windows. Interesting. Maybe I need to look at getting new video recording software rather than changing my disk hardware configuration.
Well, you can't always know beforehand how large the file needs to be. But you can
reserve some minimum size, and then make sure you write largeish buffers. Dunno if there's some additional ways to say "hey, I'm gonna write a lot"...
If you have a partition that's mostly used for large files, you can reduce fragmentation by increasing the cluster size. If you almost solely use it for video editing purposes, you might want to try going as high as 64kb cluster size. This of course requires reformatting (or perhaps using one of those partition managers)
Looking at ntfs.sys, it seems like the "ContigFileAllocSize" option isn't used - but it might still be worth a try, if you don't feel like reformatting. Catch is that, if it works, it'll affect all partitions and not just your video partition, and it could increase fragmentation for partitions with smaller files. Googling for it, as always, gives a lot of "yes it works", "no it doesn't work", "omfg you're a fool" kind of posts - so better experiment yourself (remember, you need a reboot after setting the value).
It seems that NT is still a bit conservative in some areas - like wanting to find a good fit for small writes, rather than trying to keep each file contiguous.