Slow write speed

Hi, best wishes for 2019!

I've noticed lately that my writing speed is quite low.
I mean when I copy/paste a large file from one disk to another, or from one disk to an USB external HDD.

Things I tried already:
- Disk Cleanup
- Ccleaner
- DISM.exe /Online /Cleanup-image /Scanhealth
- sfc/scannow
- chkdsk /f /r c: & also my External HDD

No problems found in each individual operation.

Quick system specs:
Windows 10 Pro 64 bit Version 1809 Build 17763.195
OS, Drivers, and most of my Software is fully up to date.

Any ideas, tips or tricks to increase my write/read speed?

Copy and paste is the worse way to copy a big file robocopy built in cmd is the fastest

Hi Samuria, thanks for the tip, wasn't aware of that function.

To copy large files, open cmd.exe as Administrator & enter:
ROBOCOPY /?

More info can be found here:
robocopy | Microsoft Docs

Although your answer was interesting, I still wonder why Windows fluctuates so much in data rates while copy/pasting. I mean the accompanied windows while doing the copy/paste operation illustrates the data rates and that ranges from a few tens of kb's to several mb's and back again. The mini-chart which shows the progress is very choppy. Almost like a stock chart with lots of peaks and troughs.

If my memory serves me right I thought this process went smoother and above all more consistent and steady in data transfer.

My computer (HP Pavilion Elite) is about 10 years old. Still using USB 2...

Some even down power when not in use. This might need to be turned off in many cases

How do I turn this feature on/off?

Thanks CountMike, I implemented your suggestion, will see how it goes...

Depending on the file Anti virus can slow it to a crawl as it scans on read and write as well robocopy by passes that as it was built for servers