Every PC musician's goal is to achieve low latency, but once you drop below about 12ms, CPU overhead will start to rise, simply because of the frequency of interrupts, each consuming its own small amount of overhead. I carried out a few quick tests with my Echo Mia to demonstrate my point, and found that on a typical Cubase SX song CPU consumption was fairly constant down to about 12ms (512 samples at 44.1kHz), but with a 6ms setting it rose by about 10 percent, and at 3ms by a hefty 40 percent. Similarly, Sonar 2 rose by about 25 percent when I dropped its Effective Latency from 12ms to 6ms, by nearly 70 percent at 3ms, and 100 percent at the lowest 1.5ms.
