Did you try the actual Passmark Support Forums?
There is an entry specifically addressing this error message (below)
“If you are seeing this error on the disk test, then it means that the data read from the disk is not the same as the data written to the disk. Normally this is a fairly serious error because it can lead to file corruption on the disk.
In the detailed error log file you should find some additional details for this error that show the value that was read from the disk and the value that was expected.
Most of the time the fault is with the disk itself but on rare occasions it can also be caused by bad RAM. This is becuase some of the system RAM is used to buffer data being set / received from the disk.
Even more rare would be something like a design flaw in the disk controller or MB that causes failure under high load when using multiple drives.”