ApexSpeedExperiment_1.cls

/*
    Speed Test - Does System.Debug() cost CPU limit?
    Author: 0to1Code.Com
*/
public class ApexSpeedExperiment_1{
    
    //Experiment 1 : Without Debugs
    public static void runExperiment1(){
        List<Lead> leadLst = [select id,name,company, Address, Industry, AnnualRevenue from lead limit 2000];
        
        system.debug('CPU Limit Consumption Start: '+Limits.getCPUtime());
        
        for( lead l : leadLst ){
        
        }
        
        system.debug('CPU Limit Consumption End: '+Limits.getCPUtime());
    }
    
    //Experiment 2 : With Debugs
    public static void runExperiment2(){
        List<Lead> leadLst = [select id,name,company, Address, Industry, AnnualRevenue from lead limit 2000];
        
        system.debug('CPU Limit Consumption Start: '+Limits.getCPUtime());
        
        for( lead l : leadLst ){
            system.debug('Printing Debug: '+l);
        }
        
        system.debug('CPU Limit Consumption End: '+Limits.getCPUtime());
    }
}