Creating ISOs takes ages, copying files manually is quick

Discussion in 'General Hardware Issues' started by schl0nz, Dec 8, 2014.

  1. schl0nz

    schl0nz New Member


    I would like to pick up from a few old threads:


    Here's what happened to me:
    I copied my windows installation from a 250GB Seagte HD via gparted to a 1TB Seagate HD. Everything else hasn't changed. I expected things to be a bit faster, but in daily work it feels the same.

    Now here's the big ouch: doing a DVD copy with CloneDVD2 took ~10mins for ripping a DVD to HD, then another 2mins to create the ISO (to an external USB3 drive).
    With the new drive, the ripping takes same amount of time, but creating the ISO would take like 30 minutes!

    I watched the process in perfmon and I could see that doing manual file copies in an explorer window would do ~100MB/s, sometimes 150, and the IO size would be anywhere from 1 to 4 Megabytes.

    During the CloneDVD copy process the IO size would permanently stick to 32 kilobytes, and due to the fact that a normal HD can do no more than around 100-120 IOPS, the reulting transfer speed is 3MB/s, ergo half an hour or more for 5-6 GB. The allocation size of the NTFS is the same for both HDs, 4kB.

    Any specific reason why CloneDVD would suddenly want to stick to 32 kilobytes?
  2. schl0nz

    schl0nz New Member

    I'll try to get the old HD running and see what the IO size was before, or why else the old transfer would possibly have been so quick.
  3. schl0nz

    schl0nz New Member

    Hi again, just did as I said, a rip to ISO with the old HD, and here's a screenshot. No, it's not an SSD.


    So, the copy process is always using 32kbyte IOs, but somehow manages to get done thousands of IOs, 1606 in this case, I also saw 1900 and more. Is something going wrong with writing sequential files? Are they getting fragmented a lot (in the first step) so that they cannot be streamed to the ISO quickly?
  4. schl0nz

    schl0nz New Member

    Wow, 109 views in a week, no ideas anyone?
  5. i7win7

    i7win7 Well-Known Member

    I don't know if gparted is adding overhead to your disk I/O (since it allows disk resizing). I can tell you the fastest disk I/O is to physical drives not to partitioned drives. Windows has a redirector that has to be called to translate logical drive locations to physical drive locations.