I was wondering if the fact of switching CPU's could generate errors for WU's caught in the midst of the change. Example from i7950 to i7980X.
They start crunching with one CPU type and finish with another.
In general there is an update of the BIOS and then a switch of the CPU. In theory there should be no difference, except speed up or new threads added.
Boinc restarts and recognizes that new threads are available and fires them up but I got some Beta and DDDT2 errors I found pretty strange.
Here under the error text.

Example 1:

Result Log
Result Name: ts06_ b013_ pr23b0_ 6--
<core_client_version>6.10.18</core_client_version>
<![CDATA[
<message>
riture impossible sur le piphique spifi (0x1d) - exit code 29 (0x1d)
</message>
<stderr_txt>
INFO: No state to restore. Start from the beginning.
forrtl: severe (29): file not found, unit 30, file C:\ProgramData\BOINC\slots\2\fort.30
Image PC Routine Line Source
wcg_dddt2_charmm_ 00B15D6E Unknown Unknown Unknown

Stack trace terminated abnormally.

</stderr_txt>
]]>


Example 2:

Result Log
Result Name: BETA_ ng599_ 00062_ 19--
<core_client_version>6.10.18</core_client_version>
<![CDATA[
<message>
CreateProcess() failed - Acc refus (0x5)
</message>
]]>