Complex sentence: As clock speeds are increased components will ultimately stop operating reliably, even if voltages are increased to maximum safe levels, or fail permanently; the maximum speed is determined by overclocking beyond the point of instability, then accepting a slightly lower setting.
Split into simpler sentences: As clock speeds are increased components will ultimately stop operating reliably, or fail permanently, even if voltages are increased to maximum safe levels. The maximum speed is determined by overclocking beyond the point of instability, then accepting a slightly lower setting.