If you need 100 clock cycles per brute-force check, you can brute-force 40 million cases per second.

8-million is actually very small. Modern computers (GPUs really) are on the order of reasonably brute-forcing 2^40-ish search spaces these days (or one-in-a-quadrillion, depending on the complexity per check)

~1GHz clock on GPUs x 4096 shaders == 4-trillion gpu-shader core cycles per second. If you're willing to wait 1-hour (3600 seconds), that's 14-quadrillion gpu-shader clock cycles.