[ChuckMcM]

And that is why it is such a great tool for learning. Lets start here:

   > I/O: * SS10 -- Fast SCSI: 80 Mbit/sec theoretical max 
   > * Rpi -- USB2 480 Mbit/sec. Now there are certainly 
   > complaints about poor USB performance, but it's not 
   > so bad that the SS10 would beat it

The SBus[1] is slower than High Speed USB[2], and yet the amount of code it takes to get 1 megabyte of data from a USB peripheral into the memory of a CPU is greater. USB is polled, the Host Controller has to continually check to see if there is something out there, SBus is not allowing it to initiate transfers from the peripheral. Further things like key presses compete with network packets for attention from the root HUB. While transactions on the Sbus(es) can happen in parallel.

Then there is the SDIO interface for the RPi's flash disk, which also competes with USB for I/O cycles on the ARM AHB bus. So at the end of the day some things are really faster (like graphics) and some things slower (like I/O), and the whole package feels remarkably similar. Can't argue on the price though, you still can't get a working SS10 for $35 as far as I can find.

[1] SBus specification -- http://bitsavers.informatik.uni-stuttgart.de/pdf/sun/sparc/8...

[2] My go to USB spec site -- http://www.beyondlogic.org/usbnutshell/usb1.shtml

[3] Summarized SS10 information -- http://www.obsolyte.com/sun_ss10/

[4] Gateway to the simplified SDIO specs -- https://www.sdcard.org/developers/overview/sdio/sdio_spec/