Question File copying slow for the first copy, fast for all subsequential ones ?


Jun 3, 2018
Hi all,

laptop: Legion 5 Pro, Windows 10 Home 21H2, Ryzen 7 5800H, 32GB of RAM, RTX 3070, 1TB NVMe SSD + 2TB NVMe SSD

copying and moving files started to be extremely slow, but only the first time around a specific file gets copied or moved. If I move a file between two drives or make a copy of that file, the transfer/copy speed is only around 10MB/s while the SSD runs at 100% active time. The moment the transfer/copying is finished, if I make another copy of the same file, or move it between the two drives, the speed returns to around 2 - 3 GB/s for each subsequential copying or moving of the file.

For the second copy, it doesn't matter whether I make another copy of the original file or a copy of the copy, anything to do with that original or copied file is going to be as fast as it's supposed to be. I can even delete the copy and just keep moving/copying the original file around and the speed won't drop. Until I try to copy/move a different file. I need to let the slow copying process finish the first time, if I copy a file and cancel it half way through, then copy again, the subsequential process is still going to be slow until the whole slow copying is finished at least once.

Things I have tried:

I checked the SSDs with the manufacturer's SSD toolkit software and no issues were found
I checked the read/write speeds with CrystalDiskMark and nothing has changed there, around 3.4GB/s read, 3.4GB write speed as it used to be
I did restart the laptop several times
I scanned the folders to be copied with Windows Defender as I thought it might have been scanning all the files while copying, but that didn't help
There are no pending updates, Windows says it's up to date

I have come to a conclusion this isn't an issue with the SSD since the subsequential copying/moving of any file happens at the "full" speed, also the write speed doesn't seem to be affected, benchmarks also return good results, games load as fast as they used to (subjectively). Would anyone be able to help with this issue?


Take a look at what the laptop is doing or may be trying to do when files are being copied.

You can use Task Manager and Resource Monitor to observe how system resources are being used when copying begins and then as copying continues.

Use both tools but only one tool at a time.

Open the tool, move the window to one side, and watch until the laptop stablilizes.

Then launch a copy and watch what changes. What resources are being used, to what extent (%), and what is using any given resource during the copying process and any related actions.

May take a bit of trial and effort to work out the testing/discovery process. Be consistent and change only one thing at a time.

Look for something running in the background or perhaps being launched when copying is being attempted.

Check indexing as well.

As always, be sure that all important data is backed up at least 2 x to locations off of the laptop. Verify that the backups are recoverable and readable.