Issue Details

I saw on the NI Shop page that the PXIe-8301 allows up to 2.3 GB/s data throughput, while the PXIe-1083 allows up to 2 GB/s data throughput. Is this information accurate?

Solution

2.3 GB/s (for PXIe-8301) and 2 GB/s (for PXIe-1083) are raw bit rates or transfer rates, which include overhead during write-to-host memory testing. Note that this is the peak unidirectional transfer rate.

Below are the results of some unofficial testing on the maximum payload rate during simultaneous write-to-host memory and read-from-host memory operations with a 128B payload size. Performance will drop for smaller payload sizes due to the overhead being the same for smaller payload sizes. Please note that the data below are not warranted. The data provided is for reference purposes only and may vary on a case-by-case basis.

1. Raw bit rate is the raw transfer rate in the physical layer while the payload rate is the useful data transfer rate received after removing overhead.
2. The unidirectional read-from-host memory raw transfer rate is around 1.7 GB/s max.
3. The numbers in the table are system bandwidth, not peripheral slot bandwidth. You will need to further divide them to get the bandwidth for each slot.
4. PXIe-8301 payload rate is better in Gen 3 chassis because PCIe Gen 3 overhead is less than Gen 1 or Gen 2