I have an issue that involves a lot of files that average about 2.5K and because the filesystem NTFS uses 4K blocks, the size on disk is considerably larger. I am wondering if any CD file systems are a lower number such as 512 bytes or 1024 bytes? This would allow for a closer number between the actual size and the size on whatever filesystem I put it on. I heard ISO9660 uses 1024 bytes by default. Anyone have any ideas?

I don't know about a freeware program, but Partition Magic by Symantec will change the size to 512 on your existing NTFS drive if that is what you want. Haven't looked at that program in a long time, so I don't know how much it costs. I think the latest version is 8 or 8.1.

Thank you for the reply, I know partion magic is a good program and very useful, but what I have is a program that creates a whole bunch of files (anywhere from 10,000 - 250,000) 2.5K on average sized files. With that many files under 4K there is a big difference between size and size on disk. This is primarly going to be used on CDs and just wondering if there is a CD filing system that would have a lower byte allocation?

Max...is archiving your files in a single compressed ZIP or RAR file is an option for you? If so, grouping them in one file would solve the cluster sizing problem.