Calculate transfer speed from PC to external HDD

linustalman · 09-01-2013, 03:11 AM

Hi.

Is it possible to calculate the transfer speed from my PC to external HDD? For example when using Grsync, the transfer speed it not shown. I'm using a USB 3.0 port so would like to know if it is using near to that speed.

Thanks.

business_kid · 09-01-2013, 03:45 AM

2 ways:

hdparm -Tt /dev/whatever
or
time cp X Y where X is a knowable size and Y is some dir on your disk

cascade9 · 09-01-2013, 06:43 AM

Quote:

Originally Posted by LinusStallman

I'm using a USB 3.0 port so would like to know if it is using near to that speed.

It wont be. Current HDDs simply cant go as fast as USB 3.0.

USB 3.0 = 5 Gbit/s (call it 500MB/sec..though I have doubts that USB 3.0 will ever get that speed). If you have a fast current HDD it might be able to get to 150MB/sec. 100-120MB/sec is more realistic.

lazac · 09-04-2013, 09:57 AM

If the HDD has a cache memory (probably it has), then I think, data transfer rate can temporary be higher than the speed required for physically reading/writing the disk (100-150MB/s). So using "time cp X Y" command with a several MB file (same or less than the HDD cache size) will use the USB 3.0's bandwidth. Anyway, the measurement will not be accurate, as this process will take much less than 1 second.