Home/ Questions/Q 466689
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-12T23:30:20+00:00

I have an Intel Core 2 Duo CPU and i was reading 3 files

  • 0

I have an Intel Core 2 Duo CPU and i was reading 3 files from my C: drive and showing
some matching values from the files onto a EditBox on Screen.The whole process takes 2 minutes.Then I thought of processing each file in a separate thread and then the whole process is taking 2.30 minutes !!! i.e 30 seconds more than single threaded processing.

I was expecting the other way around !I can see both the Graphs in CPU usage history.Some one please explain to me what is going on ?
here is my code snippet.

 foreach (FileInfo file in FileList)
{

   Thread t  = new Thread(new ParameterizedThreadStart(ProcessFileData));
   t.Start(file.FullName);  

}

where processFileData is the method that process the files.

Thanks!

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    The root of the problem is that the files are on the same drive and, unlike your dual core processor, your hard drive can only do one thing at a time.

    If you read two files simultaneously, the disk heads will jump from one file to the other and back again. Given that your hard drive can read each file in roughly 40 seconds, it now has the additional overhead of moving its disk head between the three separate files many times during the read.

    The fastest way to read multiple files from a single hard drive is to do it all in one thread and read them one after another. This way, the head only moves once per file read (at the very beginning) and not multiple times per read.

    To optimize this process, you’ll either need to change your logic (do you really need to read the whole contents of all three files?). Or purchase a faster hard drive/put the 3 files in three different hard drives and use threading/use a raid.

    • 0