The result is larger file is more than 2x slower!! (48MB/s vs 17. To test this, I use CrystalDiskMark to compare between 100MB and 2GB file size speed. They will even drop from MB/s to KB/s rate after a while, and then go back up, and then drop down again. But if the file is large (more than 1-2GB) The cache will be filled up and the speed will drop down as the flash drive controller can’t keep up. This because of the writing cache/buffer. The transferring speed advertised for your Flash Drive is usually the theoretically maximum speed (notice the word “ Up to“) When you start copying the file, you’ll notice a sudden burst of speed. So if you have multiple devices on that hub then you shouldn’t be surprise if it’s slow. Moreover, USB Hub shared bandwidth among all devices currently plugged in. However, we usually see slower speed or even file corruption when Flash Drive is plugged into USB Hub (especially a cheap one!) Try using your Motherboard’s USB 3.0 port when possible. Last I did the aggregation and still very slow transfer but a bit more stable above 20Mb/s.
![usb 3 transfer rate really slow usb 3 transfer rate really slow](https://www.easeus.com/images/en/screenshot/todo-backup/guide/classify-usb-ports.jpg)
Theoretically USB Hub shouldn’t slow down the transfer rate. Third i tried USB 3.0 and i got xtremly fast transfer and way faster when transfering from the USB of course ruling out any harddrive problems. If you’re copying the entire folders to Flash Drive then you should try zipping it as one big file.
![usb 3 transfer rate really slow usb 3 transfer rate really slow](https://www.partitionwizard.com/images/uploads/articles/2020/07/external-hard-drive-transferring-so-slow/external-hard-drive-transferring-so-slow-thumbnail.jpg)
Transferring multiple files is very much slower due to lots of overhead. Transferring 100MB file and 100 of 1MB files is not the same.