The problem though, with the argument hdd just can't keep up with Win10 is that problem, while fairly common, is not massively pervasive. I have to believe that a large majority of Win10 installs are still on spinning drives.
There seems to be no one process that  is the culprit but there are a few that are consistently involved on my computer and others. Seems these processes might have something in common that trips up Win10 on some systems but not others. 

filtersweep
 
Seems these processes might have something in common that trips up Win10 on some systems but not others. 

That's the assumption that I followed, when I noticed a freshly upgraded Windows 8.1 to Windows 10 Home laptop started exhibiting this behavior.   Windows 8.1 did not do this on the laptop.  My clean install of Windows 10 Pro on my home built DAW desktop with SSD did not do this.
 
So I spent days trying to wrangle this down to a process or two.  Shut down Cortana, search, indexing, updating, Windows store and all apps, etc.  Seems that there are still various Windows system processes and scheduled tasks that kick in after a boot with high disk utilization, and if I just let them run to completion, the laptop is happy and works normally (until the next boot).

abacab

filtersweep
 
Seems these processes might have something in common that trips up Win10 on some systems but not others. 

That's the assumption that I followed, when I noticed a freshly upgraded Windows 8.1 to Windows 10 Home laptop started exhibiting this behavior.   Windows 8.1 did not do this on the laptop.  My clean install of Windows 10 Pro on my home built DAW desktop with SSD did not do this.
 
So I spent days trying to wrangle this down to a process or two.  Shut down Cortana, search, indexing, updating, Windows store and all apps, etc.  Seems that there are still various Windows system processes and scheduled tasks that kick in after a boot with high disk utilization, and if I just let them run to completion, the laptop is happy and works normally (until the next boot).

One thing that is clear to me is that you and I seem to have the exact same problem! Like you, if I let the computer do it's thing for however long, sometimes 15 or 20 minutes, it will then run flawlessly, until I reboot. I think a problem with the drive is unlikely (unless it is the software controlling the drive and I have no idea what brand/model of drive is installed}. Also unlikely to be a corrupt install of Windows I think. Seems more likely a system setting issue or maybe a drive controller that just doesn't work correctly with current versions of Win10. Not sure I mentioned this before, but my problems did not start until after at least of couple a Win10 updates, but have been consistently present ever since they started. I am going to poke around more at MS. Hard to believe that this issue does not drive a lot of people crazy enough to get MS attention.

I wondered about the drive in my laptop, especially since it is a 5400 rpm HDD. 
 
But when I restored my desktop, Intel Ivy Bridge chipset, Samsung EVO SSD image onto a Western Digital 1TB 7200 rpm HDD, and booted my desktop with that, I saw the same problem.  Hmmm...
 
My laptop is an Acer Aspire E-15 with a Haswell Intel chipset, an Intel Core i5-5210u, and a Seagate SATA III 500GB HDD.
 
All drives pass hardware diagnostics and benchmark tests 100% as expected.
 
Anyway, since the laptop is not my primary PC, I am willing to live with this vs. spending any more time pursuing it.  Wouldn't surprise me a bit if it mysteriously fixes itself with some MS update down the road ...sigh...

My i3 Win10 (Creators) laptop does NOT behave this way.  It runs like it is supposed to with HDD

BobF
My i3 Win10 (Creators) laptop does NOT behave this way.  It runs like it is supposed to with HDD

I'll let you know if it works that way on mine, AFTER I get around to updating to Creators... 
 
Sticking with Win 10 Home 1607 (Anniversary) for now.

abacab

BobF
My i3 Win10 (Creators) laptop does NOT behave this way.  It runs like it is supposed to with HDD

I'll let you know if it works that way on mine, AFTER I get around to updating to Creators... 
 
Sticking with Win 10 Home 1607 (Anniversary) for now.

I didn't have the problem on 1607 either.
 
Hopefully Creators will solve whatever the problem is.

As Jim says fastboot could be the cause.
If not try to deactivate Telemetry service.

As Jim says fastboot could be the cause.
If not try to deactivate Telemetry service.

I am on 1703. It doesnt seem specific to the version. I did notice though that since May 2017 my laptop has failed to install an HP system driver 14 times. Checking the error code (sorry, not with me right now) gets a lot of hits but no fixes. I think the problem developed around that time so maybe related??? All the win10 updates say they installed correctly since then but this driver update continually fails.