about the same , real cylinder pressure is what really determines fuel octane need simply put to much compression will build too much heat & ignite the fuel before spark , keep increasing pressure & you have a diesel !! There are other factors too , lighter cars with more gear will get away with more cylinder pressure due to reduced load against the engine , powrband also makes a difference for example my Duster used Speed Pro 6 pack pistons with milled closed chamber iron heads & steel shim gaskets so the mathmatical compression was approx 11:1 but it had no sign of detonation on pump gas but it was never loaded below 3000 rpm & used the Mopar .590 solid cam , but quench was perfect , it could be easily made to detonate at low rpm but was never used this way , put that engine in a 1 ton truck & pull a trailer with it , it won`t live long !!
there is no calculation for real world use with all the variables possible