The older computers also ran around 1 to 4 megahertz (MHz), whereas the Raspberry Pi runs at 700 MHz. And the Raspberry Pi is far from the average home PC. Today, boxes with 2 GB RAM and 2 GHz processor speed are common.
ASIO is a standardized way of describing the communication between audio software and a piece of audio hardware. It enables audio hardware manufacturers to write optimized drivers for their hardware that bypass the potentially high latency operating system mechanism for supporting audio hardware.
Now that the majority of audio interfaces have ASIO drivers, Microsoft's Sound Mapper device is almost completely redundant. However, in some cases it can be useful. For example, if you need to play old multimedia files, Sound Mapper can be used, as it can play back files with sample rates as low as 6kHz.