If you don't have a low latency ASIO sound card no problem!
with asio4all you can achieve a better latency in Windows using any sound card.
Sdrconsole does not support ASIO, Powersdr does.
In Linux use Jack real time audio with real time kernel.
If you don't wanna compile things, download Ubuntu Studio, it comes with real time audio out of the box.
You can achieve better than 30 ms audio latency with Ubuntu Studio and Linhpsdr,
haven't tried Sparksdr yet.