doubts regarding clock frequency of 18f4550

i have doubt regarding oscillator frequency.
i am using 18f4550, XC8 compiler, primary oscillator of 20MHz. i am keeping following configuration

#pragma config FOSC=HS, FCMEN=ON, WDT=OFF, IESO=ON, XINST=OFF, LVP=OFF
#define _XTAL_FREQ 20000000

so it cleared that i am using machine cycle of 5MHz frequency.

bit 4-3 CPUDIV1:CPUDIV0: System Clock Postscaler Selection bits
For XT, HS, EC and ECIO Oscillator modes:
11 = Primary oscillator divided by 4 to derive system clock
10 = Primary oscillator divided by 3 to derive system clock
01 = Primary oscillator divided by 2 to derive system clock
00 = Primary oscillator used directly for system clock (no postscaler)
For XTPLL, HSPLL, ECPLL and ECPIO Oscillator modes:
11 = 96 MHz PLL divided by 6 to derive system clock
10 = 96 MHz PLL divided by 4 to derive system clock
01 = 96 MHz PLL divided by 3 to derive system clock
00 = 96 MHz PLL divided by 2 to derive system clock

if i configure the above as divide by 2 for primary clock then is my machine cycle frequency get double?

means as they given that each clock cycle get divide by 4 for 1 machine cycle then will get divide by 2?

how to check frequency on which pic is running using pickit3 ??