4 ms·
USB 3.0 speed limit is 5Gbps. That's 625 MB/s, which is faster than any HDD I'm aware of. Modern USB 3.2 can do 20 Gbps. That's 2500 MB/s.
by bufferoverflow 6y ago
USB 3.0 speed limit is 5Gbps. That's 625 MB/s, which is faster than any HDD I'm aware of.
Modern USB 3.2 can do 20 Gbps. That's 2500 MB/s.
- jolmg 6y agoI'll check what the speed was again, when I get back home.
- jolmg 6y agoOk, so I got it connected via SATA. I tried the following: pv /dev/zero > /mnt/foo umount /mnt # trying to get rid of any caching of foo. mount /dev/sda4 /mnt pv /mnt/foo > /dev/null pv /dev/sda3 > /dev/null pv /dev/zero > /dev/sda3 All pv invocations showed an average of ~126MiB/s each. I don't have another HDD on hand to compare since I've upgraded everything to SSDs. Though I don't remember what's normal for HDDs, to be honest 126MiB/s doesn't seem that slow. I thought I remembered something lower.
- fulafel 6y agoNot relevant here but a tangent: In USB 2.0 times the efficiency was pretty terrible, you could get ~25 MB/s disk transfer throughput from the 480 Mbit/s signaling rate. It improved a little over the years... I wonder what are the actual speeds you can get from USB 3.0/3.2.
- bufferoverflow 6y agoLook at USB 3.2 SSDs and NVMe enclosures. They go over 1000 MB/s for sequential reads. https://www.anandtech.com/show/14661/usb32-g2-portable-ssds-roundup/3 https://www.anandtech.com/show/14661/usb32-g2-portable-ssds-... I'm pretty sure they are limited by the USB <--> NVMe controller, not USB itself.