back to article Is eSATA really better than USB 2.0 and Firewire?

I am looking to buy an external hard drive and I am impressed with the speed of an eSATA connection - 300MBps, it's claimed. Is it really this fast in real life? Or is it just as fast as Firewire? If it is not as fast as its advertised, why not?

COMMENTS

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  1. Anonymous Coward
    Anonymous Coward

    Yes

    USB 2 offers 480Mbps (Mega-bits per second), and Firewire offers 400Mbps.

    In the real world you don't get close to that kind of throughput, eSATA doesn't get its theoretical throughput either, but it offers 3000Mbps (That's 375 Mega-bytes per second).

    A modern hard drive can go faster than X% of the USB and Firewire connections, but won't be held back by X% of an eSATA connection.

    Also; the hard drive is designed to run on SATA, id doesn't have to run through any conversion circuitry, further slowing you down.

    Yet more; eSATA gives you Native Command Queuing, reducing average seek times.

  2. Ross Talbot

    Yes and No

    What Bracken has said is true however do not expect to get transfer times of 480Mbps, 400Mbps or 3000Mbps as at the end of the day the hard drive in these units are 99% of the time standard 7200rpm drives.

    This is where the bottleneck comes from as most 7200RPM drives you will be luck to get 70Mbps out of them.

    So in reality the difference is so minimal that you or i would probably never notice the difference.

    The Hard drive has always been one of the worst bottlenecks within a computer hence the release of SSD (Solid State Drives) which are basically big memory sticks.

    Hope this helps

    Ross Talbot

  3. Paul

    It's all a matter of purpose.

    eSATA on it's own doesn't really offer any direct benefits over firewire or USB2.

    However eSATA is designed primarily for hard drives or other ATA compliant devices. USB and Firewire are designed for many many uses. So logic would say if you've got an eSATA port available, you may as well use it because it's not going to be used for much else, whereas a USB or firewire port could be.

    Also bear in mind firewire and USB are daisy chain technologies. This meaning that your 400 or 480mbit/s is shared among all devices connected to a root hub.

    So if you were to have a USB hard drive on a root hub along with a 300mbit WIFI "n" adaptor your hdd and 300mbit wifi would share the same 480mbit.

    Conversely with eSATA the only thing it's likely to share bandwidth with is your other HDDs. Unless in raid you're not likely to read from more than one disk at a time in such a way that'll cause bottlenecks.

    A quick note about SSDs. They are not "faster" than magnetic storage. They have a very low random access time. However, as you will find by running HDTach on a Flash drive, the sustained read / write speeds are lacking way, way behind that of magnetic storage and RAID setups. This is great for sticking your virtual memory on and for server based OS drives and such where things like registry are rarely referenced and written sequentially, but for the average Joe who wants to copy files to a DVD, install programs, play games etc SSDs will seem slower loading/saving things than a well kept magnetic drive.

  4. John Kirkham

    Forget about eSata

    It's worthless. I've tried so many eSate connections on external hard drive enclosure's and they don't damn well work. Stick with USB.

  5. R. Herschel Wyatt

    Title

    I have all three types of external drives attached to my computer so I just ran a brief test ... here's the result:

    USB 2.0 Burst - 29 MB/sec ... Avg 29 MB/sec

    FW Burst - 40 MB/sec ... Avg 40 MB/sec

    eSATA Burst - 115MB/sec ... Avg 58 MB/sec (this is a SATA 1 drive)

    eSATA is clearly superior in all respects.

    One of the advantages of eSATA is that is is not seen as a removable device by NT based O/Ses and you can easily install your O/S on an eSATA drive.

  6. Paul

    Re: Title

    "I have all three types of external drives attached to my computer so I just ran a brief test ... here's the result:

    USB 2.0 Burst - 29 MB/sec ... Avg 29 MB/sec

    FW Burst - 40 MB/sec ... Avg 40 MB/sec

    eSATA Burst - 115MB/sec ... Avg 58 MB/sec (this is a SATA 1 drive)

    eSATA is clearly superior in all respects.

    One of the advantages of eSATA is that is is not seen as a removable device by NT based O/Ses and you can easily install your O/S on an eSATA drive."

    I think you'll find Burst rate is dragging that average up misleadingly. And the USB result looks to be flawed in some way, just tested my 2.5" 5400rpm drive and got 38MB/s, and that's a pretty old one.

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