Hi Lars, The USB 2.0 Specification says max 480Mbps, and is to be considered a theroretical max. This equates to about 60MBytes/second.
The devices that connect through the bus rarely get even close to this rate. In fact, if you compare it to the SATA-2 specification says 3000Mbps (375MBytes/second, roughly 6 times faster than USB 2.0). Disks on SATA-2 Controllers sometimes achieve as much as peak of 100MB/s write performance which equates to about 800Mbps, (and this is for rather fast disks, the average write speed is somewhere around 65MBytes/second when directly connected to SATA-2). This shows that the specification is a lot higher than the actual throughput you get. Your external disk is connected through a USB 2.0 Connector, and the disk itself is connected through a controller (probably PATA or SATA) in the disk housing. There are many bottlenecks between your soekrisbox and the actual disk, limiting the transfer rate quite a lot. 1. The soekrisbox itself, and it's USB 2.0 controller. 2. The Adaptor in the disk enclosure (from USB2.0 to SATA/PATA). 3. The disk itself (could be limited by a number of things, such as the rotational speed of the disk etc). 4. Never believe marketing! They never show the real performance, only the thoretical, not limited by all the bottlenecks. I would say that your speed of 5,3MBytes/second, is not to far off what to expect. You could obviously test this on another machine to find out *where* the bottleneck is. If you get substancially higher speeds, then you know it is the controller in your soekrisbox... Cheers, Simon. On Fri Nov 14 10:25 , "Tom Van Looy" sent: >Is it slower than the USB is *supposed* to be? USB is not fast. The external disk is a: http://www.wdc.com/en/products/products.asp\?driveid=333 It has: Serial Bus Transfer Rate (USB 2.0) 480 Mbits/s (Max) The soekris port is 2.0 capable "usb0 at ehci0: USB revision 2.0". I'm getting an average transfer rate of 5350 KB/s. By the way, the internal disk is a: http://www.wdc.com/en/products/products.asp\?driveid=477 Kind regards, Tom ------------------------------------------------------------------------- FC% din egen, gratis e-postadresse pC% Start.no
