Interface Transfer Rates

Transfer rates depend on a number of factors, including the device accessed the type of transfer, and cycle usage.

The table below includes typical transfer rates for the Optibit and USB interfaces at a 50% cycle usage with RP/RX and RZ devices.

Interface	Transfer Type	RP	RX	RZ
PO5/PO5e/FO5	Read	1.5	4.0	8.0
	Write	1.0	1.0	8.0
UZ3	Read	NS	NS	6.0 *
	Write	NS	NS	6.0 *
UZ2	Read	1.5	1.5	NS
	Write	1.0	1.0	NS

Transfer rates are in MB/s. NS: Not Supported

* UZ3 transfer rates are highly dependent on the specs of the computer.

Because of the overhead required to poll the hardware or run single commands with the USB interface, users should be aware of the following relationships when performing small data transfers with the UZ2.

Interface	Transfer Type	RP/RX
UZ2	Snippet Transfers (~100)	0.3 MB/s
	Single Commands	1000 Commands/s

Cycle Usage and Large Transfers

The following graphs show how the cycle usage affects the transfer rate for large transfers with the Optibit, Gigabit, and USB 2.0 interfaces with an RX device. The data was collected using a buffer size of 1,000,000 for the Read Tag and Write Tag commands. The transfer rates were tested using both the RP2.1 (a single processor device) and only the main processor of an RX6 and using circuits generating cycle usages of 5, 25, and 50 percent.