ClearCube I/Port Users Guide User Manual
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I/O-intensive applications between the host and the I/Port can significantly affect
performance. ClearCube offers these recommendations:
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Do not use I/Ports for writing to CDs or DVDs. Mass-storage devices such as CD
burners and DVD burners rely on a predictable and relatively constant data transfer rate
from the source to the burner. Although modern burners have large write buffers, the
likelihood of a buffer underrun is high, and increases both with recording speed and with
file size. If the user must write files from a host to CD or DVD, use the USB 2.0 connector
on the front of the ClearCube PC blade.
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Do not use I/Ports to transfer extremely large files. Although the I/Port provides robust
file transfer capabilities, the limited bandwidth inherent in RDP can cause these file
transfers take an exceedingly long time. If the user must write extremely large files to a
blade or to the network, use the USB 2.0 connector on the front of the ClearCube PC
blade.
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Do not write large files directly to I/Ports. The RAM disk on the XPe I/Port is limited to
16 MB, and is reserved as a temporary space for updating software on the I/Port. Attempts
to write a file larger than 16 MB to the RAM disk will fail. Attempts to write a series of
files with a sum file size greater than 16 MB will eventually fail when the 16 MB limit is
exceeded.
Individual files with a file size greater than 56 MB cannot be written through the I/Port to
an attached USB peripheral storage device. This is by design, and represents a security
feature that limits moving large files such as software. Folders containing multiple files,
with a total size greater than 56 MB can be written through, as long as the 56 MB limit is
not exceeded.
The Flash disk in the I/Port is write-protected by the Enhanced Write Filter. Writes to the C:\
drive, including temporary files, are written to an area in RAM that is separate from the RAM
disk and is shared by the operating system. When the sum of the files and the operating
system’s RAM requirement exceeds the total amount of available RAM, the I/Port will suffer
a system error. This can be cleared by rebooting the I/Port. However, data in RAM cannot be
recovered.
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For normal usage, leave the Write Filter turned on. This prevents persistent writes to
the Flash disk and helps keep the device secure. Since applications are actually run on the
host in an I/Port environment, there is no need for the user to write data to the local I/Port.
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Upstream audio is not supported by RDP. Microphones can only be used as local
devices on the I/Port, and not as I/O devices to send content to the blade. This is a
limitation of RDP.
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Lengthy RDP sessions may result in slower throughput. If the connection through RDP
appears to have slowed down significantly, close the RDP session and restart the I/Port.
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Test your USB peripherals before putting them into a production environment.
I/Ports are USB 1.1 or USB 2.0 compliant, depending on model number. I/Port
peripherals, including USB devices, rely on redirection by RDP to work properly. RDP
can only redirect the following devices: mass storage, printers, serial ports and smart card
readers. ClearCube Technology maintains a list of peripherals (including USB devices)
that are fully tested and certified for use with ClearCube-supplied thin clients, including
I/Ports. This list is kept up-to-date and is available on the ClearCube Support Web site at
http://support.clearcube.com/
as Technical Bulletin TB0109, Certified Peripherals for
C/Ports and I/Ports. Because of the wide range of peripherals available, ClearCube is