Classic case: Customer reports in “SharePoint Online performance is slow. [period]”
Account Manager, Product Manager, Project Manager comes running 4 weeks after due date, customer wont accept the solution with the given performance. Ok…. Lets gather the tools for first steps:
Compare performance from your location with the client location using the Browser development tools. Are they the same?
If yes, problem usually lies in the configuration of SharePoint Online. Start testing from your location and don’t bother asking customer for client computer, remote login, network information.
If no, problem usually lies from customer client machine and SharePoint Online server. Start testing from customer client machine at their location. Ask them for information regarding their network configuration. Do they have proxy? Are they running old router/switch between?
When you have determined the location of your challenge, proceed to second step.
Second step of troubleshooting SharePoint Online performance is to measure ping time to the tenant as well as traceroute in order to locate route and geolocation of the tenant.
I use the following to complete that, either run it myself or ask the client to run it from their location.
psping.exe -n 20 tenant.sharepoint.com:443 > PsPingResult.txt
timeout 30 /nobreak
tracert tenant.sharepoint.com > TracertResult.txt
timeout 30 /nobreak
From that I derive the following:
1: For optimal performance, ping time is between 30-50ms stable.
2: Number of Route hops between 12-15.
3: Use https://www.iplocation.net/ to get most likely geolocation of tenant from returned public IP.
Psping.exe is part of SysInternals PSTools package.
Lastly again back to developer tools.
Collect performance report and look for errors in the console. Look for external http requests, certificate validation errors, script errors.
What the numbers show you
A: Ping times of more than 50MS or route hops more than 12-15 would lead me to look at the network with possible causes being:
Linespeed, old or outdated network equipment, tenant geolocation, proxy filtering, non-optimal routing.
B: Usually there are little or no problems in the direct network measurement and it will come down to the browser Development Tools. Note the difference between DOM loaded and Fully rendered. Client really dont care about DOM download, as they are only interested in the fully rendered page. So what can be causes of slow rendered pages:
Certificate errors, script errors, poor client hardware, proxy filtering, Antivirus, Poor coding.