Any plans for PXI express??

[M.haefner]

Hi,

since the Virtex 5 offers high performance, I'm curious if NI plans to introduce a PXI-express version of the FlexRIO.

Regards,

Matthias

[Ryan_V[DE]]

Hi Matthias,

Thank you for your post. NI is always looking to push the envelope in terms of performance, largely driven by customer demand. What features of a PXI Express FlexRIO would be most beneficial for your application? Increased bandwidth to the host? Dedicated bandwidth to the host (for multi-card systems)? Improved clocking and synchronization? Your feedback is much appreciated!

Regards,

Ryan

[M.haefner]

Hi Ryan,

my application would be a continuous streaming with a data rate of up to 50MB/s. With the PCI7833 I could reach approx. 20MB/s via DMA-Transfer. The question is, if I can reach 50MB/s with a Virtex5 and PCI/PXI. Since I'll have other PXI hardware in the system, I have a doubt, that this can be guaranteed at all events. Do you know what is the bottleneck for DMA-Transfer to the PCI7833?

Regards,

Matthias

[Ryan_V[DE]]

Hi Matthias,

I'm not sure of the limitations of the PCI-7833... perhaps BrowningG can comment on that module. As for the the PXI-795XR, you should have no trouble approaching streaming rates of 120 MB/s. There is one caveat in that you cannot send data to a device that fast in a PXI Express chassis such as the 1062Q, 1065, or 1075. This is due to the PCIe to PXI bridge in the chassis, which has asymmetric DMA rates. Streaming from an FPGA module to the host around 120 MB/s should be fine.

With other instruments in your system, it really depends on what you are doing. As long as they are not transferring "a lot" of data continuously and you use reasonably large buffers on the host and FPGA, 50 MB/s on one of our Virtex-5 devices should be easily achievable. One thing to note is that you must use a 32-bit data type for your DMA transfer to hit this rate - 16-bit data types are not packed into 32-bit PCI bus transfers by default.

Please let us know if you have any other questions.

Regards,

Ryan