How to optimize windows10 - XP still seems faster

Please clarify- when you say - I think it was 163s for your SSD with 20H2 boot time.. was that the time for a cold boot to the lock screen being displayed?

With a SSD that should be around 12-14s, for example, depending on precise hardware params and possibly software.

To analyse a slow boot (and there have been reports of this - feel free to search tenforums for e.g. 'slow boot') you can use the Windows Performance Analyser (free from MS).

You can find examples of its use and screenshots if you search tenforums.

Using this tool is somewhat techincal. It gives a graphical representation of events vs time, so it can be seen where undue time is spent. Perhaps only one member here is particularly familiar with its use.

Did your boot time increase suddenly after a feature update (upgrade), for example? Was there a point at which this occurred?

I'd suggest trying Safe Mode boot and see it it is still slow to boot in Safe Mode.

Boot into Safe Mode on Windows 10

If it's a much faster boot in Safe Mode then I'd ask what security software you have installed?

Then I'd check event viewer for clues.

See Posts #3 & #4 here:

PC boot time suddenly increases

If you import custom views into Event Viewer check Event ID's 101, 102, 103, 106 and 109

Find whatever is taking the longest. I would suspect a service under Event ID 106.

Other than that it might be trial and error to eliminate possible culprits.

Perform a Clean Boot in Windows 10 to Troubleshoot Software Conflicts

You could just try removing Avast using the dedicated uninstaller then reboot and test. If it makes no difference you can reinstall Avast.

Using the Uninstall Utility for Avast Antivirus | Avast

I will rephrase, as they say in court:

What is the time for a cold boot to the lock screen being displayed?

Long clarification: I want to be sure you are not automatically logging in (no login prompt) and therefore giving a time after startups have been executed.

*** you say:

I was just wondering why win10 is much slower and want to debug that issue.

I have already stated the appropriate tool to use, other than trial and error.

Now that's important clarification - so you mean your basic boot time to the lock screen is around 12-14s or perhaps a bit more.

After that, what startups do you have?

Tools:
a. task manager list
b. Autoruns (free from MS) - lists everything- far more than the task manager.