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Comment by mikewarot | Hacker News Reader

It is amazing that we can do A/D and D/A at anything faster than audio... let alone 28 GHz D/A and 20 GHz A/D. The hardware required to anything more just process the samples at those speeds and do anything more than frequency shifting is one of the compute intense things I can imagine.

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It's very rare to actually utilize the full bandwidth of the ADC to do any processing in these. The data gets immediately decimated down.

Correct. If you look at the block diagram of the AD9084 (from the article link), it has on-chip DUC (Digital Up Converter) and DDC (Digital Down Converter) blocks.

https://www.analog.com/en/products/ad9084.html

That's not really true, there's plenty of applications that use these sort of bandwidths. A big one is optical communications (28 GHz bandwidth is actually not super high there), but also some specialised microwave comms and radar/military. They alm do processing at 10s to 100s of GS/s (obviously highly parallel).

While full bandwidth applications certainly exist, it is rare. Most direct sampling schemes are used for having a purely digital RF front end within the Nyquist range of the ADC/DACs. It's cheaper and easier to develop firmware/gateware than debug analog RF issues and respin hardware.

That's not even crazy considering you can do tens of Teraflops/s on modern GPUs.

Get your data into the system via PCI-E, do some RDMA magic to get the data onto your GPU and put the cores to work.

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