The state of the art in super-fast PRNGs is about 0.3 cycles per byte at the moment. I believe this is done with SIMD versions of the xoroshiro algorithms right now. 0.3 cycles per byte compared to "a few" cycles per byte is an order of magnitude difference in throughput.
Still, most crypto libraries are designed with extreme performance in mind, and very few PRNG libraries are. You can do a lot better than 0.3 cycles/byte and still beat the NIST test if you try for speed.
Here's the comparison from the maintainers of Julia: https://prng.di.unimi.it/#shootout
Still, most crypto libraries are designed with extreme performance in mind, and very few PRNG libraries are. You can do a lot better than 0.3 cycles/byte and still beat the NIST test if you try for speed.