When you must use binary mode

Two histogram steps in optdiag output can show the same value due to loss of precision, even though the binary values differ. For example, both 1.999999999 and 2.000000000 may be displayed as 2.000000000 in decimal, even though the binary values are 0x3fffffffffbb47d0 and 0x4000000000000000. In these cases, you should use binary mode for input.

If you do not use binary mode, optdiag issues an error message indicating that the step values are not increasing and telling you to use binary mode. optdiag skips loading the histogram in which the error occurred, to avoid losing precision in sysstatistics.