These tests are automatically run when you start up AXD Mac OS X tools.
SMBIOS tests check to see if bad memory was detected and mapped out at Xserve
startup. When the Xserve tests memory at start up, it automatically maps out bad
memory. Mac OS X doesn’t see this mapped out memory, so the non-SMBIOS memory
tests don’t test it. The SMBIOS test reports these mapped out DIMMS.
When an ECC error occurs, memory catches the problem and and fixes it. When you run
other memory tests, the tests don’t realize an error has occurred. The ECC tests detect
these memory fixes and report them.