Sorry, my mistake. Cell overclock is kind of a mystery, there's only one known multiplier at the time (which can make the clock go up to 4.8 GHz).
https://www.psx-place.com/threads/cell-cpu-oc.38081/
I wonder if @aomsin2526 have researched about this CPU or XDR RAM overclocking. The post from LuanTeles was from 2022 before this genius started to make miracles in the scene with qCFW, badWDSD, badHTAB, etc.
