I didn't think I would have another update around this issue, but I stumbled on something related to this issue. 

I have been running the 7.0.0 Build 16324942 code for some months now on these machines with no issue. 

Under this release, the microcode versions are all correct/consistent on all cores shown in the output below.  It is only when I try and move to 7.0.1 does the microcode version become inconsistent.  This now leads me to believe that this is not bios related, but related to the microcode update done by ESXi.

I tried catching one at the first boot after upgrade from 7.0.0->7.0.1 and inserting "microcodeUpdate=FALSE" at the end of the boot string, but I am still getting a purple screen showing microcode mismatch.

Is there another way to prevent/disable the microcode update at boot time?

[root@esxi3:~] vmware -l
VMware ESXi 7.0 GA
[root@esxi3:~] vsish -e cat /hardware/cpu/cpuList/0 | grep -i -E 'family|model|stepping|microcode|re
vision'
   Family:0x06 
   Model:0x4d 
   Stepping:0x08 
   Number of microcode updates:0
   Original Revision:0x0000012d
   Current Revision:0x0000012d
[root@esxi3:~] vsish -e cat /hardware/cpu/cpuList/1 | grep -i -E 'family|model|stepping|microcode|re
vision'
   Family:0x06 
   Model:0x4d 
   Stepping:0x08 
   Number of microcode updates:0
   Original Revision:0x0000012d
   Current Revision:0x0000012d
[root@esxi3:~] vsish -e cat /hardware/cpu/cpuList/2 | grep -i -E 'family|model|stepping|microcode|re
vision'
   Family:0x06 
   Model:0x4d 
   Stepping:0x08 
   Number of microcode updates:0
   Original Revision:0x0000012d
   Current Revision:0x0000012d
[root@esxi3:~] vsish -e cat /hardware/cpu/cpuList/3 | grep -i -E 'family|model|stepping|microcode|re
vision'
   Family:0x06 
   Model:0x4d 
   Stepping:0x08 
   Number of microcode updates:0
   Original Revision:0x0000012d
   Current Revision:0x0000012d
[root@esxi3:~] vsish -e cat /hardware/cpu/cpuList/4 | grep -i -E 'family|model|stepping|microcode|re
vision'
   Family:0x06 
   Model:0x4d 
   Stepping:0x08 
   Number of microcode updates:0
   Original Revision:0x0000012d
   Current Revision:0x0000012d
[root@esxi3:~] vsish -e cat /hardware/cpu/cpuList/5 | grep -i -E 'family|model|stepping|microcode|re
vision'
   Family:0x06 
   Model:0x4d 
   Stepping:0x08 
   Number of microcode updates:0
   Original Revision:0x0000012d
   Current Revision:0x0000012d
[root@esxi3:~] vsish -e cat /hardware/cpu/cpuList/6 | grep -i -E 'family|model|stepping|microcode|re
vision'
   Family:0x06 
   Model:0x4d 
   Stepping:0x08 
   Number of microcode updates:0
   Original Revision:0x0000012d
   Current Revision:0x0000012d
[root@esxi3:~] vsish -e cat /hardware/cpu/cpuList/7 | grep -i -E 'family|model|stepping|microcode|re
vision'
   Family:0x06 
   Model:0x4d 
   Stepping:0x08 
   Number of microcode updates:0
   Original Revision:0x0000012d
   Current Revision:0x0000012d