Sure, I will try with hdl_2014_r2. What software (bare-metal) is to be used with this? Can you please confirm the version label for it.
Also, I tried using hdl_2014_r1 (hdl and no-os software) and changed the rate to 1 and 3. I have captured the spectrum analyzer plots. You can see the doubling of the frequency. As you know when we use the DMA data by defining DAC_DMA, the output frequency should be 2.4 GHz + 960 KHz. But, with rate set to 1, the output frequency is 2.4 GHz + 1920 KHz.