I own Sony Vaio Z laptop with two external USB ports. It's quite new and has USB 2.0 support. I'm using Vista x64 on it.

I also have two external usb hard drives, Iomega 500GB and WD for 1TB. Every hard drive has USB 2.0 support.

I connect two devices to my laptop and trying to copy date from one hard drive to another. But it takes a lot of time! The speed is about 15 Megabytes per second. I have to wait toooooo long to copy all the information from one hard drive to another.

When I try to copy information from my internal (SSD) hard drive, it works fine for both external drives. The speed is very high and it shows me something about 100 Megabytes per second. It makes me feel that USB 2.0 is OK on both drives.

But when I'm trying to copy from one external drive to another external, I still get very low speed.

I checked out Device Manager and here is the settings I have:

(sorry, can't upload image because of my rating, check this url: http://picbite.com/image/122073daljo/ )

I think it's because two of my external drives use the same USB 2.0 controller.

Is there any way to make it work faster? Is it possible to move one of my USB ports to other USB 2.0 controller?

Or is there any software which can help me to automate copying all the files thru my internal drive? I have only about 3 gigabytes free space on internal drive and it's quite difficult to move manually every file from one hard drive to internal and then again to another internal.

  • superuser would be a better fit. – Dayton Brown Mar 15 '10 at 17:51

USB2 running in "hi-speed" can theoretically do about 60MBps (MegaBYTES) maximum (AKA 480Mbps), but you'll never get that.

If you are using both drives on the same USB hub (as it appears in the picture), then you are sharing that available bandwidth between the devices. So at theoretical best (with both drives being accessed) you'd probably only get like 30MBps to each drive. After adding overhead and real-world physics to the mix, then getting ~15MBps (BYTES) sustained sounds about right to me.

You're not going be able to reassign which USB ports are attached to which hub, without some very good soldering (at least). :)

You're going to want to get that 2nd drive onto a different USB hub, or hooked up via Firewire, eSATA, or alike to get it onto a different data bus.

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The max transfer rate for USB 2.0 is around 15-20 mbps. So you can't expect higher speeds.

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  • 1
    Wrong. It's up to 400 Mbps. – Roman Mar 15 '10 at 17:57
  • 5
    You're both wrong it's 480Mbps – anon31097 Mar 15 '10 at 18:31
  • And that transfer speed is TOTAL, so if you have one drive transferring in and one drive transferring out then each drive will operate at half the bandwidth of a single drive transferring in (or out). Consider using firewire (if you have it) for one of the HDDs, that way you can fully utilise the USB bandwidth in one direction, and use the firewire interface for the other direction. – PP. Mar 15 '10 at 18:36