If there are USB 2.0 devices plugged into the same USB bus, you could be falling back on all ports, effectively slowing down the USB 3. And yes, those little bursts of information across the USB wire might be at the theoretical speed, but there is so much "other" things that goes on during a file transfer that you are only sending those little bursts with a lot of time doing nothing. Yeah, you will never get theoretical max nor anywhere near it when looking just at one file. And then the operating system (as I have found out) still does so much disk activity and calls to the file system related to the file you are transferring, in addition to all the other things the operating system dopes. When it comes to USB, it is not quite the same, but you are still talking through a USB hub which is on a bus to the CPU of your system on which your computer operating system runs. but the answer is generally delayed sine a simple yes cannot be transferred on the first letter. Now imagine if that is a relay between 5 intermediaries, some of which can start relaying as you are still speaking. Yes, the average talking speed of a human is around 200 words a minute, but imagine you have to wait until you are allowed to talk and then after 20 words you have to stop and wait for the listener to tell you he heard you before you ask if it is ok for you to can speak the next 20 words. I always use this analogy when talking about internet speeds. Then there is the traffic cops and handshakes that get involved. Transfer speeds on USB are defined as the theoretical maximum if it is a constant burst of transfer in a nice controlled environment. Just order of magnitude should / should not be better in this situation?Ĥ0MB/s is mega bits per second. I am NOT looking to quantify the transfer rate to 3 decimal places. But would you accept 70MB/s from a USB 3 in real life? Yes, I know - there's theoretical speeds and then real life.
#USB 2 VS USB 3 READ SPEED FULL#
The 150GB file is all that's on either of them (so not an issue with a drive almost full / can't find free sectors). The drives have a 3.0 port but the drive inside is crap? or even a 5400RPM drive transfers faster than usb3
#USB 2 VS USB 3 READ SPEED HOW TO#
Start copying again and file explorer shows it as about 70MB/s.īetter, but not anything near the 625MB/sec that 3.0 should get.Īny thoughts on how to figure out the bottleneck? A bad cable? the computer? the computer ports aren't really 3.0? I move that drive to the front so both are in USB 3 / blue USB ports. So, then I realized 1 drive was plugged into a USB 2. That's megabytes per second, right? Googling USB transfer rate, I find pages like this I have to transfer a 150GB file between 2 recently bought USB 3.0 external hard drives using a recently bought HP desktop and this is a good chance for me to clear up my ignorance of transfer speeds.Īt first, the source USB drive was plugged in the back of the desktop (the USB ports are black there) and the the target drive was plugged into a front blue USB port (and these say SS with the USB logo).ĭrag and dropping in file explorer (win 10 with 8 GB RAM), it showed a graph of the transfer and said the speed was around 40 MB/s.