This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(99.2, 74%, 19%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EPF%3C/text%3E%3C/svg%3E)
Hi,
after upgrading my two PC to Windows 10 2004 I'm experiencing on both slow writing on USB 3 key encrypted with bitlocker.
With previous Windows version writing speed was about 20 MB/s, now speed swings from 8 MB/s to 0.
With the same USB key not encrypted the writing speed is about 18 MB/s, a bit slower than with the previous Windows version.
USB 3 chipset is not the same on the PCs, one is Intel and the other is ASmedia.
Any idea on how to fix this issue?
Thanks
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(108.80000000000001, 40%, 20%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ECC%3C/text%3E%3C/svg%3E)
Hi，
Have you tried install the latest update？please make sure your system has been updated with the latest package August 11, 2020—KB4566782 (OS Build 19041.450).
We also suggest to press the Windows key + X to open the Device Manager and get the update on USB driver and motherboard driver.
Yes I've the latest windows update and the latest USB drivers.
I've also tested the latest USB drivers from Microsoft Catalog and the latest USB drivers from the manufacturer.
I suspect this is a bitlocker issue :-(
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(22.400000000000002, 28.000000000000004%, 12%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ESK%3C/text%3E%3C/svg%3E)
Same issue with me it's BitLocker problem my speed was 25 to 30MB/s but after upgrade windows, my speed becomes 5 to 6mb/s. Bitlocker works good in the existing system but after upgrading or reinstall windows it's copy speed become very slow
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(265.6, 13%, 35%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EX%3C/text%3E%3C/svg%3E)
Same here. After the recent update (built 19041.450), once bitlocker is turned on for my 1TB flash drive, amazingly, the write speed drops by almost 10X (from ~250 MB/sec) to about 25 MB/sec. Look forward to a fix.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(105.60000000000001, 8%, 20%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EA%3C/text%3E%3C/svg%3E)
I have the same problem on my PC. Addtionally, I found this problem still affecting disk performance greatly in latest windows 10 21h2 and even in windows 11, 2 years after build 2004 released.