So, I was copying stuff onto people’s external USB HDDs… mostly movies… the thing is that I had to copy from multiple folders onto their HDD… and the way it works with external HDDs is that if you copy multiple files in parallel, the combined time taken is waaaaaaay more than doing the same copies sequentially. This is because of certain limitations
1. Your comp’s main HDD has a limited number of read/write heads.
2. The external USB HDD has a limited number of read/write heads.
This translates to the same head moving around repeatedly in case of parallel transfers. It invariably so happens that the time it takes for the head to move is a lot and the net data rate reduces.
So, what is needed is some sort of a utility that can make the copying sequential… something that will let you queue up stuff…
One such free thing is TeraCopy http://www.codesector.com/teracopy.php One warning about this thing though… of the nearly 30-40 times that I used it, it crashed twice while trying to copy files… dont know why… but it didnt repeat, so its happy now 
One dangerous thing about it though is that after you select a file and decide to remove it from the copy queue, delete will try to delete the file from the main HDD!!
I am writing my own thing in C# .NET just for fun (multi threading et al)… will probably blog about it again later….
So, thats it… TeraCopy… I am calling mine OmegaCopy 
