Re: [Discuss-gnuradio] interfacing a DSP array card to USRP2

[Firas Abbas]

Hi,
> From: Jeff Brower <address@hidden>

> That's huge... and you  mentioned a 64k block transfer, much smaller, but 
> still more than 40 times a 
> large Ethernet packet.  It sounds to me like this particular card mfg 
> was focused on very high rate streaming (without gaps or drops) and not on 
> low-latency, small transfers.  I would guess they didn't set up their 
> driver to optimize small transfer sizes.  Maybe even the board didn't 
> support a small size, for example if the FIFO had to contain a minimum number 
> of channels and/or data length before it could assert "not 
> empty".
> 
>-Jeff

I agree that may be the driver is not optimized to transfer small  packets. In 
this card, you can setup number of samples in the packet. The problem was if 
you configured it to transfer 1024 complex samples or 32K complex samples, the 
latency is the same.


Best Regards,

Firas