Chapter 2
NI 5450 Overview
©
National Instruments Corporation
2-69
NI PXIe-5450 User Manual
Streaming to Multiple Channels
To stream data to multiple channels, you must provide data that is
interleaved. For example, to stream I16 data to two channels, you must
interleave channel 0 and channel 1 samples, so the first sample will go to
channel 0, the second to channel 1, the third to channel 0, and so on. You
cannot stream to two or more channels with individual, non-interleaved
writes for each channel.
Average Performance Rates
The following tables list the average data rates possible for PXI, PCI, and
PXI Express signal generators. Average data transfer rates are highly
system dependent. The following table is intended to give you an idea of
the average sustainable transfer rates using 16-bit (or 2 byte) samples.
PXI and PCI
PXI Express
Data Source
Data Rate (MB/s)
*
Host memory on desktop computer or PXI
embedded controller
~90 to 115
Desktop IDE or SATA hard drive
~55 to 70
†
Laptop or low RPM hard drive
25 to 30
†
Host memory on desktop across MXI-3 to
PXI board
25
Host memory on desktop across MXI-4 to
PXI board
25
*
All data rates highly dependent on chipset.
†
Measurements were taken using the Windows API for unbuffered file I/O.
Data Source
Data Rate (MB/s)
*
Host memory on desktop computer or PXI
embedded controller
~524
Desktop IDE or SATA hard drive
~310
*
All data rates highly dependant on chipset.
†
These numbers were obtained using several file I/O optimizations.
