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On-access scan slow down the performance of my iMAC


I bought an iMAC in July 2018. However the on-access scan of sophos  dramatically slow down my iMAC. Every time, when i open a new program, it will take more than 30 seconds to open it with the on-access scan on. After I turn off the on-access scan, everything went well. Do anyone have any ideas?

  • Hi Fang,

    Which exact setting when turned off in Sophos Home portal resolves this issue for you? 

    Can you please let me know the version of MacOS running on the computer and also try reinstalling Sophos on that machine and see if that helps. 

    Open activity monitor while you are experiencing/expecting a slowdown and see what processes are running and consuming a lot of CPU% when you're having that problem. This might narrow down the issue.  

    It is worth noting that we might need to investigate this further and have a deeper look into it. So my recommendation is to contact Sophos Home support and open a ticket. (If you have a premium license.)  

  • In reply to Yashraj:

    Hello Yashraj,

    Thanks very much for your response. My macOS system version is macOS High Sierra 10.13.6. 

    I did not do any extra setting except turn the on-access scanner off in the preference. 

  • In reply to Fang Zhilong:

    Hi Fang,

    Please help me out with the following:

    Fang Zhilong


    I did not do any extra setting except turn the on-access scanner off in the preference.  

    1. Please let me know which option did you turn off in your Sophos Home portal which results in a performance increase. I was not able to find a specific option to turn off "On Access scanning".

    2. Did you notice any process eating up resources in activity monitor when the slowdown occurs? 

    3. Please reinstall the Sophos software once.

    4. Are you using Sophos Home Premium or just Sophos Home?