USB-3 Flash Memory Sticks – Read and Write Speeds

Last year I bought a coupler of faster USB-2 Flash sticks and was actually delighted with their read and write performance of 35 MB/s and 12 MB/s respectively compared to cheaper devices which were much slower. But the size of files I occasionally have to transfer between between devices keeps growing and 2 GB files are no longer the exception. In other words, I have to wait again two to three minutes for a file to be copied to the memory stick. Since then, however, I've upgraded to USB-3 on the PC and USB-3 capable flash memory sticks have become much cheaper. Since their advertised read and write speeds are phenomenally higher I tried my luck with a Transcend JF780 32 GB stick which is advertised with read and write speeds of 210 MB/s and 75 MB/s respectively. And here is the result I achieved in combination with my rather 'underpowered' Intel i3 notebook that has two USB-3 ports:

Write Performance

When copying a large 1.6 GB file to the stick from a non-encrypted partition of my notebook's solid state disk, the sustained data rate was 59 MB/s. This is 5 times faster compared to writing the same file to the USB-2 stick I bought a year ago (which I did again this time around just to make sure the stick is still fast and the new notebook compared to a year ago has no influence on the result). In other words, while the file takes over 2 minutes to be copied to the USB-2 stick, it copied to the USB-3 stick in just 27 seconds.

Read Performance

Read performance is even more breathtaking. Reading the file from the USB-3 flash stick and writing it back to the SSD after having ejected and reinserted the stick to make sure the file or a part of it is not read from memory) the sustained data rate was 100 MB/s which corresponds to a transfer time of 16 seconds for the 1.6 GB file.

Running the same benchmark program as in the year before resulted in a maximum read performance of 214 MB/s (without writing the data to another volume) and an average write rate of 29.6 MB/s as shown in the screenshot on the left. The write rate is lower in the benchmark because as far as I can tell, the program performs random writes, which is slower than to write a continuous file to the stick.

Price

The USB-2 8GB Transcend memory stick cost around €10 one year ago vs. €30 for the 32 GB Transcend memory stick with USB-3 this year. So while the per GB price has dropped, the overall price of the stick has increased. Cheaper USB-3 models are also available but their advertised read and write speeds are around 50 MB/s and 15 MB/s respectively. In other words, speed still has its price.