Unlike the [[Commodore 64]] and [[Atari 8-bit]] computers, the MSX standard mandates the same Z80 CPU clock speed (3.579545 MHz, exactly the NTSC color subcarrier frequency) for both PAL and NTSC machines.
However , PAL and NTSC still have to be taken into consideration when developing a game, as there is less time to do updates at 60 Hz than it does at 50 Hz. In games made for 60 Hz, the CPU sits idle for 20% of the time when running at 50Hz. Conversely, games which are made for 50 Hz and which utilise the full CPU can not run properly at 60 Hz.
This is why when developing a game, it’s best to make it targeted for 60 Hz. Then it will be much easier to get it to work at both frequencies.