National Instruments 653 Series User Manual page 117

Optimizing Your Transfer Rates
Determining the Maximum Transfer Rates
© National Instruments Corporation
Use this appendix to determine the maximum transfer rate for your device,
optimize transfer rates, and to see example benchmark results.
The maximum sustainable transfer rate an NI 653X can achieve depends on
the minimum available bus bandwidth and is based on your computer
system. The maximum sustainable transfer rate also depends on the number
of other devices generating bus cycles, your operating system, and your
application software. The maximum sustainable transfer rate is always
lower than the peak transfer rate.
The average bus bandwidth requirements differ between specific NI 653X
devices. Here, the NI 653X devices are listed in order of their average bus
bandwidth requirements, from highest to lowest:
• NI PCI/PXI-6534
• NI PCI/PXI-6533
• NI AT-DIO-32HS
• NI DAQCard-6533 for PCMCIA
♦
NI 6534
With the NI 6534, if the data you are acquiring/generating fits in the
onboard memory, the transfer rate is not limited by the bus bandwidth,
only by the maximum transfer rate based on the protocol used. These rates
are listed in Table E-1. The peak transfer rates are based on a system with
a 1-meter cable.
Table E-1. Peak Transfer Rates Based on Mode and Protocol Used
Mode/Protocol
Handshaking 8255
Handshaking Level-ACK
Handshaking Leading-Edge Pulse
E-1
E
Peak Rate (MS/s)
4
2.86
2.86
NI 653X User Manual