Why is my download of macOS so slow when my download speed is over 150mbps?

I am downloading macOS Sonoma with my current OS Big Sur and it is taking a very long time. I did a speed test and my download speed is over 150mbps. Any thoughts on why this is happening?


iMac (2017 – 2020)

Posted on Mar 24, 2025 6:18 PM

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Mar 25, 2025 1:32 AM in response to rerudnick

Patience and more of the same, patience


A watch kettle will never boil


There are factors:


Some which are beyond your control and those with are totally under your control


1 - Software on the computer interfering with the download process including AntiVirus Software


Notation: Disabling the AV Software may or may not solve the issue.


Removal of the AV Software may increase the chances of the download to perform as expected.


2 - Running behind a VPN which may increase Packet losses or corruption of the download 


3 - Turn off any Third Party Two Way Firewall and try again 


4 - If via wifi  & too many Other devices using the wifi at the same time reducing the Bandwidth to your computer. 


5 - Best Results are via Ethernet Cable to Router


6 - Restart in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal 


Try Again using the Software Update Applet in System Preferences / Setting 

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Why is my download of macOS so slow when my download speed is over 150mbps?

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