Yes, current microcode version is 0x12d for all cores. But there is a difference between cpu0 and cpu1-7
[root@xxxxx:~] vsish -e cat /hardware/cpu/cpuList/0 | grep -i -E 'family|model|stepping|microcode|revision'
Family:0x06
Model:0x4d
Stepping:0x08
Number of microcode updates:1
Original Revision:0x00000121
Current Revision:0x0000012d
[root@xxxxx:~] vsish -e cat /hardware/cpu/cpuList/1 | grep -i -E 'family|model|stepping|microcode|revision'
Family:0x06
Model:0x4d
Stepping:0x08
Number of microcode updates:0
Original Revision:0x0000012d
Current Revision:0x0000012d