Discrepancy in bytes??

[csonni]

A post evolving from my other post (disappointment in backup)- I have 2 identical folders- 1 as source and 1 as destination (distination being copied / backup with Deja Vu.  Source Folder size is 10.67 GB  on disk (11,446,417,844 bytes) and destination folder is 10.67 GB on disk (11.445,864,622 bytes).  I opened a folder of images inside the both folders that also was off in size and checked the size of each image in each folder, and they were identical in size, yet the get info on the folders didn't agree.  What's up??!!  And why does 10.67 GB end up being 11,446,417,844?  Isn't that 11.45 GB?  I just want to be sure I have a backup program I can trust without having to do get infos on individual folders.  That's rediculous.

[giantmike]

Well, I have a question about where these folders reside. If they reside on different disks, they may be slightly off in size due to how big each block is on the disk. IF they are on the same disk, they may be different size due to some invisable files taking up slightly more space in one spot than the other.

As for memory math, it uses the Base 2 system instead of Base 10. Thus, a kilo is 2^10 (which is 1024) instead of 10^2 (which is 1000). If you do the math here, you get 11,446,417,844 bytes / 1024 bytes per kilobyte / 1024 kilobytes per megabyte / 1024 megabytes per gigabyte = 10.6603073 gigabytes.