@paulb_nl: there are some advantages by keeping HPLL2x enabled even if optimizied modes. After previous changes, random phase error due to HPLL2x should be much smaller (between 1/12th and 1/8th of a dot) as multiple samples per dot are captured. Apparently it’s still noticeable though, so I’ll need to consider removing HPLL2x from those modes. It’s also possible to enable finer tuning of samplerate in optimized modes if needed, but available precision would then depend on line multiplication mode.
@Calle W: To calculate exact refresh rate, you’ll need to know exact pixel clock frequency, number of dots per line and lines per frame. Assuming that in N64 320×240 the said parameters are 12.170453MHz, 773.25 and 263, then v_hz = 12170453Hz/(263*773.250) = 59.845Hz.