No, the setting wasn't active by default, indicated by "dev.cpu.0.cx_lowest: C1". It would have been active if it said "dev.cpu.1.cx_lowest: C3" because the lowest C-State your processor supports is C3 ("dev.cpu.0.cx_supported: C1/1/1 C2/2/1 C3/3/35"). You thought that C1 is the lowest C-State because it has the smallest number, however, that is not the case. The higher the number of the C-State the more power saving it is.The C-State trick did absolutely nothing for me. I'm glad OP had success in reducing its "environmental footprint" by doing something entirely free, but for my server, I don't see a single watt reduction from my UPS readings... Perhaps the setting was somehow active by default? Perhaps these CPU's are so old they don't fully support the parameters? ( I highly doubt).
Did you change the tunables to C3 instead of C1? If not then it's no wonder that you see no difference in power consumption.