System and compressed memory high disk usage during file copy

I have win 10 64-bit home on a 4th gen core i5 laptop. I have a WDC 1T 2.5" USB3 drive. It is about half full. It used to do 60-70MB/s write speed. Since a few days ago, I noticed it has slowed down by a factor of 5-6 to 10-20MB/s. While copying large files, I watched what's going go. The System and compressed memory process was doing a lot of read and write on the disk. If the copy speed reported by the dialog is 15MB/s, then system compressed memory process is reading 15MB/s and writing 30MB/s. It looks like this process is reading back the content written to the disk and writes back. It is consistent over reboot with several large files from 200MB to 7GB in size.

A couple of weeks ago I did a file backup. I created a 5GB virtual drive on my SSD and dumped all files to be backed up. Took only 5 minutes to copy the files to the virtual drive and copy the virtual drive file to the WDC disk, at around 67MB/s, typical of this type of portable drives. While I was wondering what was going on, I tested the same files with a USB3 dock and a 2TB Seagate drive. Write speed is about 150MB/s. There was no sign of the system and compressed memory process hogging R/W on the drive. So I thought it was not a problem with all disks. The WDC drive has no compress to save space option, BTW. I wonder what's going on. I have AVG antivirus and I turned it off while copying and same slow 15MB/s speed. All my drives are formatted into NTFS. My main drive is SSD and the source of the large files.


Question Info

Last updated April 6, 2019 Views 13,489 Applies to:


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The issue with "System and Compressed memory" is rather a common issue that many of our users face. Please do follow the below steps to troubleshoot.

Step 1: Update all the drivers.

Please update all the drivers in Windows 10 computer and check if it works. You can do that by,

1. Press Windows key + X key and select the Device Manager.

2. Select all the drivers one by one and right click it and select "Update driver software..." and check if the issue persists.

if the issue persists, please go for the below step.

Step 2: Turn off the "Show me tips about Windows"

Please do the below steps to do the same.

1. Press Windows key + I key and open the settings.

2. In the settings, select the System>Notifications and actions> turn off the  "Show me tips about Windows".

3. Restart the computer.

If still the issue persists, please follow the below step.

Step 3: Modify the registry.

Please follow the below steps to troubleshoot. (Read disclaimer before proceeding)

1. Open Notepad and type the following.

Windows Registry Editor Version 5.00






2. Save with extension *.reg ( example solution.reg)

3. Double click the file and merge it.

4. Restart the PC

DISCLAIMER:  Important this section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. Also, please back up your data for avoiding any data loss. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft

Knowledge Base:

How to back up and restore the registry in Windows

Microsoft is not liable to any data loss or damage caused. Proceed at your own risk

Please let us know if the issue is resolved or you need any further assistance.

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