Past experience with overclocking Intel processors had discouraged me from trying to run the ESP8266 at the alternate double clock rate of 160Mhz. The “standard” rate is 80Mhz. Regardless of the CPU frequency, sampling is governed to a large extent by the speed of the MCP3208 ADCs use to sample voltage and current.
Yesterday, for the first time, I uploaded a firmware to run at 160Mhz. It has been running flawlessly now for about 12 hours. There doesn’t seem to be any heat issue either. The immediate thing that I noticed was that the 60Hz samples per AC cycle increased 10% from 640 to 700. As the SPI frequency remains the same, this would be a decrease in the time needed between samples. 50Hz should see an increase from about 770 to about 920.
Response times for graphing have also been reduced, and the cycles-sampled-per-second seems to more consistently approach the theoretical limit (40@50Hz, 33.3@50Hz).
I need to get a lot more data before I can consider operating at 160Mhz standard, but unless I find something detrimental, I intend to add an option in the configuration to do so.