How long does the 2004 upgrade take using Windows Update?

Bree · 27 May 2020

A year ago I asked (and answered) the same question for 1903. Having just let Window Update successfully upgrade the same machine I used for those tests I can say that the answer remains the same. Times for each step were almost identical - over four hours from start to a working desktop.

Bree said:

Short answer - a very long time....

....Paint would have dried quicker - it took a further three hours and ten minutes to get to "Installing - 100%" and asking me to select a restart time to complete the install...

...what would take less than two hours with an ISO (I know, because I have previously used the 1903 ISO on this machine) took over four and a half hours via Window Update....

How long does the 1903 upgrade take using Windows Update?

My recommendation: unless you really need to see the Feature Update listed in update history, then download the ISO and use that to upgrade.

How long does the 2004 upgrade take using Windows Update?-2004-update-history.png

flavallee · 27 May 2020

Bree:

I updated one of my Windows 10 Pro 64-bit computers via the Windows Update app from Version 1909 Build 18363 to Version 2004 Build 19041.

It went through the "Getting things ready" and "Downloading" and "Installing" and "Working on updates" steps and involved 2 restarts.

The entire update process took 84 minutes.

There are personalized and other settings I need to re-do, and device drivers I need to re-update.

That will add at least another hour to the process.

Frank

Samuria · 27 May 2020

I just did it 1 hour 15 mins from windows update tried media creation tool and it installed updater and said thank you for updateing and closed but got it sraight away via update

Word Man · 27 May 2020

Hmmm. I got much the same as Samuria but didn't actually time it. My guess would be 60-90 minutes straight through checking Windows Update to updated desktop. This is 100 mbps ISP across 802.11ac 5Ghz wifi starting around 16:00 GMT.

4 hours seems like a lot unless it was early in the release and server bandwidth was limited?

Bree · 27 May 2020

Word Man said:

4 hours seems like a lot unless it was early in the release and server bandwidth was limited?

No, bandwidth was not the hold up. The download was quick. It's the processing of what has been downloaded that is is time consuming.

This is only a problem when using windows update because it uses the Unified Update Platform (UUP) to perform the update. UUP is designed to reduce the download size of an update by only downloading the changes, not the full set of files as are used in the ISO. For more details on how UUP differs from a canonical upgrade using an ISO see my post from this time last year:

How long does the 1903 upgrade take using Windows Update?

UUP is processor intensive, the reduction in download size is at the expense of more processing to apply the update. I compared the total time taken by UUP with using an ISO to do the same upgrade on the same machine. The ISO method is twice as fast as letting Windows Update do the job.

How many hours that takes depend on the power of the CPU doing the work. I would expect a top spec machine to show the same factor of two difference between the two update methods. The ISO should always be the fastest way to upgrade because UUP has so much more work to do.

This was hardly the fastest machine out of the block (my System One below). Even with an ISO it takes two hours. But many users out there will have similar spec machines.