WSUS very slow synchronization (Windows Server 2019)

Julien 1 Reputation point

Hi everyone, We have setup a new WSUS server, but first synchronization is extremely slow...

We have a 10Mb/s connexion, but the synchronization use about 50-100kb/s -_-

I searched on this forum, and only found to put the BITS with foreground mode, but nothing change, and now it synchronize for 4 hours and always at 10% :'(

Why the synchronization does not use all the bandwitch ?

The connexion is dedicated to the WSUS server, and there is a proxy server.

thx in advance

Here a speedtest from the WSUS server:


Windows Server
Windows Server
A family of Microsoft server operating systems that support enterprise-level management, data storage, applications, and communications.
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  1. Rita Hu -MSFT 9,626 Reputation points

    Hi Julien-4124,

    Thanks for your posting on Q&A.

    In my opinion, the first synchronization with Microsoft Update or your upstream servers does take some time. The length of the synchronization depends on the number of products, update classifications, and languages you have selected, as well as the speed of your Internet connection.

    As a best practice, clear all classifications before we synchronize for the first time. After the initial synchronization, select the desired classifications, and then rerun synchronization.

    Hope the above will be helpful.


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