USB 3.0 SD card readers very slow compared to usb 2.0 reader


I use an SD card reader to read/write large files.

For a very cheap USB 2.0 reader, which has very slow write and read speeds, it is much faster when using bleach bit to wipe the file.

When I use a new 3.0 USB reader, using the same SD Card, the read and write speeds are very fast, about 4x the speed of reading and writing files compared to the 2.0 card reader, however using bleach bit is extremely slow on the new faster 3.0 usb card reader.

To give an example to wipe a 350 mb file with bleach bit will take 25 seconds on the usb 2.0 card reader, very fast using bleach bit. However, very slow when reading and writing files.

Using the usb 3.0 card reader it will take 2 minutes and 30 seconds for the same 350 mb file, extremely slow using bleach bit.

I tried two usb 3.0 card readers, both are new and very popular on amazon. Both used the same exact 64gb sd card.
The Transcent usb 3.0 reader
The Kingston digital usb 3.0 super speed multi card reader.

Placing the usb 3.0 card reader in a usb 2.0 slot, it will still go just as slow using bleach bit, but faster than the 2.0 card reader when reading and writing.

I am very confused here? Why would the usb 3.0 card reader, which is much quicker reading and writing files, be 5 times slower to bleachbit files? It is just so weird to be able to read and write files so fast on the new usb 3.0 card reader, but when I go to bleach bit files on it, it takes so long.

Thanks for any advice here.

You tested the same SD card on the same computer with BleachBit and another program, and the speed varied by two readers. Yes, I agree that USB 3 should be faster than USB 2.

BleachBit 2.0 introduced a feature to wipe files on Windows using the Windows defragmentation API. However, it does uses a different method for the "wipe free space" option (available in the file menu), so I'm curious if you would see the speed reversal with this process.

Other things to check is that the card is formatted with NTFS and is defragmented.

You are using Windows 10?

For troubleshooting, try to temporarily disable any antivirus/security software

Andrew, lead developer