eSATA file copy problem

When I copy large files to an external eSATA drive (~10 GB total transfer):

- The first 2 or 3 GB transfers at full speed (around 80-90 MB/s).
- After that, the transfer gets slower and slower. By the 6 GB mark, I had hit USB 2.0-like speeds (30 MB/s). For reference, the last GB transferred at around 12 MB/s.
- For about 5 minutes after the transfer was "complete" (according to Windows Explorer), the HDD activity light on the external drive was blinking. On top of that, Resource Monitor showed 8-10 MB/s writes on the external drive and a QD of 4.5, even though I wasn't doing anything else with that drive.
- During those 5 minutes, I cannot not access the newly copied files.

Is this normal eSATA behavior? Or is something wrong here? I tried turning off write caching, but it didn't make any difference.

 

Have you tried reinstalling the driver or testing the problem with another eSATA device?

 

This is really not normal for eSATA. eSATA = internal SATA with a different shape plug that hold better for external usage. That is all.
I am wondering if your internal HDD has the same problem (well you can't know.. just that large projects from programs takes longer to load than before)

This sounds like a driver bug. Uninstall your SATA controller driver (or motherboard, if you can't do it separately), and install the latest version. Try the one available on the computer manufacture web site, if that does not work, try the one on the SATA controller manufacture, and if that doesn't work, use an older version. If still not, then something is broken... but I doubt it, as it works... just gets slower over time.

 

If this is an eSATAp socket and the OP is using a single cable to connect SATA and power. Then it may be that the USB power part of the eSATAp port is not able to supply enough current for long periods of time.
I think this is a known issue with USB2.0 power supply?

 

No.
eSATA devices require it's own power, and doesn't need the power part of the USB port.

eSATAp, is for devices that are like USB memory keys... but instead of having a USB port.. it's an eSATA. Like this one:

 

eSATAp also works for drives. I've got 3 of them. It's just kinda hard to find the right enclosures. But there's a whole thread about that on here somewhere

What it sounds like the OP is running into is a highly fragmented drive. How full is the drive? The behavior you're seeing looks like it's caching the entire copy, and it's not accessible until it's done actually writing.

Are you SURE that the drive is connected via eSATA, and not via USB? What cable are you using? Because I've copied over 100GB off and onto an eSATA drive multiple times and it never slowed down.

 

I have indeed seen eSATAp drive enclosures for 2.5" drives, but this is a 3.5" dock that has its own AC power brick, so that's not the issue here.

The drive is about 25% full (2TB Caviar Green, I think I have about 400-450 GB of stuff on there).

Finally, the (internal) source drive is an Intel X25-M, which should be fast enough to keep any SATA 3.0 Gbps drive fed with data.

 

Just copied winsxs folder (5.70GB ~50000 files) from 80GB intel x25m to 2TB WD green.
Similar behaviour, started around 90MB/s, dropped to around 30MB/s by the end.

However, tried copying a single 6GB iso the same way and it stayed a steady 100MB/s +

 

And does that dock also have a USB port? If so, there's an interface chip between the HDD and the eSATA cable and i suspect that is the source of your problem.

I have one of the external eSATA/USB 3.5" / 2.5" docks and it has had erratic transfer performance (and sometimes won't connect) and is due to go into the bin once I get a replacement.

John

 

That there is your issue. Copying the ISO is exactly what is expected for performance, so that indicates there are no hardware or driver issues on your machine.

Copying lots of small files is slower, period. Especially because you're writing to a spinning drive and writing a TON of small files (average size is just barely over 100K), which means it's going in a random-access pattern. It's just the way things work. That's why even on SSDs the 4K random write scores are much lower than the 2M random writes. Random, small accesses either reading or writing will slow things down.

 

Yep, it has a USB port. From what I've heard, all of the docks are based on the same (licensed) design and as a result are essentially the same product - they've just been rebranded by different OEMs.

Actually in my case, I tried copying over a 12GB video file and had the same problem.