I'm not sure what's going on but what I am seeing makes little sense.
I have a USB sata drive attached to my desktop that I've been trying to backup to a drive pool. I used DO to start an unattended copy and had been runing for over a day. It's not even an entire drive but the files that didn't get copied due to a scheduled system restart. According to the graph I'm getting only 1mb/s.
i wasn't expecting it to have drops to 0 yet it seems faster at around 3mb/s but it's hard to understand how the dips to 0 affect overall performance unless that's what that 1.08mb/s is telling me??? I would have expected an even line. What this suggests is that the drive cannot supply data fast enough to keep the buffer full. Chkdsk ran fine and Crystal Disk reports it as a SATA 300.
Trying to diagnose why a USB 2 SATA drive isn't getting the throughput it should is a harder nut to crack. I used winsat to see what the drive would report and can see it's limited for some reason but is it a connection issue or disk issue?
I tried running winsat against the mapped drives but no go. I was curious to see that it was the same but now I don't know.
There's something else going on here too. While the copy is running I cannot access or open another lister without pausing the copy, toolbars stop responding, CrsytalDisk won't display even when it's resident, network connectivity can halt, can't open task manager or even access the icons on the taskbar, etc. It's like the copy has taken priority over the desktop interface.
Did you test the performance using File Explorer? It should be the same as in Opus.
Sounds like either an issue with hardware (e.g. too many things on the same USB hub or not enough power to the hub), drivers or antivirus delaying things while scanning the USB stick as the files are written. Unless the machine is low on memory and paging during the copy.
This drive hasn't been connected for a while because I ran out of ports on my hub. I bought a new hub that's plugged directly into the desktop but how would I know if it's under-powered? It's 2.0 10 port with an A/C adapter.
I upgraded the desktop to max memory which is 16gb double what it had.
Could also be a dodgy cable. It's hard to diagnose USB problems since there are so many components involved. All you can really do is try swapping things until they work.
In my experience though USB to SATA interfaces are not normally very fast, certainly nothing approaching native SATA speeds.
I want to wait to try replacing hardware until the current copy completes hopefully in the next couple days. The drive is a SATA 300 not the fastest but 1mb/s I've been told is slower than it should be.
A USB 2.0 cable should be able to do between 1.5mb/s to 10gb/s according to specs. I've already bought some new 1' USB 2.0 cables so a shorter length should help. They are rated at 60mb/s. I'm not sure what the drive is rated other than SATA 300 but I posted the image from CrystalDisk in the first post. I just don't know how to interprt the lingo.
I also wanted to add diskpart and Disk Manager won't run with a DO copy in progress along with the other's I listed initially. I've had this happen several times before over the years I just wasn't able to figure out it was related to the DO copy being in-progress.
Yes, it does seem consistent across anything using Window's copy/move API. I think what it is has to do with large files. I'm guessing that when it changes from one file to the next file other items that are waiting will get priority.
