Slow performance on Office365.

[Mike Azure Larsen]

Dear Tech Community, 

In our organiztion we have 35.000 users in our tenant who is experiencing slow performance on Office 365 and portal:

The 35.000 users who experience the issues are scattered accross 70 different physical locations throughout Denmark.

This performance issues affects the following:

*OneNote

*Exchange

*SharePoint

*OneDrive

*Teams

They experience highly delayed page loading times in the browser and/or timeouts when accessing those services.

I can also inform that we have tried changing our public DNS on our network, tested for max connections on public IP, proxy throttling without success

To rule out that it is related to out network performance we have also made tests on a vanilla computers without any proxy settings, antivirus, packet scanner on several different mobile (3G/4G) networks, again from different cell providers with the same result, slow performance on Office365.

Does anyone have any suggestions on what we could try next?

We do have a support case opened with Office365 Support, how can we escalate that? 

I highly appreciate any help, thank you.

Best Regards Mike

[#2]

Mike, There are many potential reasons for slow performance however practically here is a good place to start your investigations https://support.office.com/en-us/article/network-planning-and-performance-tuning-for-office-365-e5f1...

[#3]

Do you have a premier support contract in place? If so, they should help you here quite fast

[#4]

We've had poor performance recently, so we opened a ticket with Microsoft Premier Support.  They were able to track down a few of our sites/pages that were putting a heavy load on the SharePoint/SQL servers.  Microsoft did some changes on their servers and we're making changes to our pages.

One of our tasks is to optimize the views on a large list (60000+ items). 

On another page, we have list web parts that are doing audience targeting based on a managed metadata column (causing excessive SQL queries).

[#5]

Thank you John, there is a lot useful info in the article. 

Best Regards Mike

[#6]

Hi! I have several Exchange Online users who are complaining about poor performance. The issue has been there for a couple of days now. Both general browsing in Outlook shared mailboxes and mail delivery are affected negatively. My users are also located in Denmark.

[#7]

Sadly not yet. But this case that we need some sort of premier support.

[#8]

No problem Mike. I think you can tell from the responses that this is a multi-layered problem potentially. As @Deleted alludes any customisation should be on your short list to investigate. Any large organisation needs to consider a Tier 1 support contract such as Premier to expedite Microsoft support. All the best.