where is the bottleneck?

Discussion in 'General Questions' started by HC_3, Jan 18, 2023.

  1. HC_3

    HC_3 Hunter

    Messages:
    128
    I have a new ssd that is connected to the windows vm of parallels desktop.

    However, only 20-30 mbit/s (on average, read and write) are measured.

    to be precise: at first, up to 300 mbit/s are measured when writing. then the transfer rate drops steeply. when reading (initially and sometimes permanently up to 500 mbit/s) it is similar.

    no difference if i connect the ssd directly to the macbook pro (2019, intel) or via a usb-hub.

    where is the bottleneck? do you have any advice for me?
     
  2. Aydaskhan Asochakov

    Aydaskhan Asochakov Staff Member

    Messages:
    177
    Greetings,
    We've created a new ticket in our system to proceed with investigation.
    Kindly check your inbox or log into my.parallels.com > Support > My tickets.
    Let us know if you have any additional questions.
    Thank you!
     
  3. HC_3

    HC_3 Hunter

    Messages:
    128
    with a little time, i tried to narrow down the problem today.

    A new Curcial P3 SSD achieves the following transfer values:
    (numbers are rounded; first value = write, second value = read).

    Format exFAT
    directly connected to the USB-C port of the MBP
    connected to MacOS
    800 MBit/s 500 MBit/s

    Format: exFAT
    directly at the USB-C port of the MBP
    connected to Windows VM
    700 500

    Format: exFAT
    via USB hub and dock on MBP
    connected to Windows VM
    30 20

    Format: NTFS
    directly connected to the USB-C port of the MBP
    800 500

    Format: NTFS (Bitlocker-encrypted)
    directly on the USB-C port of the MBP
    300-700 500


    A three-year-old SanDisk 2TB SSD achieves the following transfer values:

    Format: NTFS (Bitlocker-encrypted)
    directly on the USB-C port of the MBP
    30-500 20-400

    Format: NTFS (Bitlocker-encrypted)
    via USB hub and dock on the MBP
    30 20
     
  4. HC_3

    HC_3 Hunter

    Messages:
    128
    the differences in the values of the SanDisk SSD are strange.

    does anyone have an explanation for this?

    one additional piece of information: since the usb problems with parallels desktop 17, the SanDisk is not recognised correctly by windows the first time it is plugged in. i always have to unplug it first and plug it in a second time. then it is recognised correctly.

    does anyone have any idea what this could be related to and how i can change it?
     
  5. HC_3

    HC_3 Hunter

    Messages:
    128
    when i tried to reconnect the SanDisk 2TB SSD and another SSD directly to the macbook's usb-c port today, they did not connect to the windows vm.

    via the usb-a hub (which is attached to the docking station on the mbp, and via an usb-c to usb-a adapter) the connection worked.

    this is strange. can anyone make sense of this?
     

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