An alternative approach that should be orders of magnitude faster
would be to sort the data ascending or descending on column 1 and
descending on column 2, then use this formula (its not an array
formula) in column D

shDAT.Range("D2").Formula="=IF($A2<$A1,$B2,$B1)"
shDAT.Range("D2").AutoFill Destination:=shDAT.Range("D2:D" & r),
Type:=xlFillDefault

Charles


The code is now:


r = shDAT.UsedRange.Rows.Count
shDAT.Range("D2").FormulaArray = "=MAX(IF(R2C1:R" & r &
"C1=RC1,R2C2:R" & r & "C2,FALSE))"
shDAT.Range("D2").AutoFill Destination:=shDAT.Range("D2:D" & r),
Type:=xlFillDefault


Execution of this part of the code is now a magnitude faster, and it
produces exactly the same result.

Calculation at the end of the code (when calculation is set to
xlCalculationAutomatic again) is of course still slow, but this is
expected.
One does not simply walk into 10K array formulas and expect it to be
fast. ;-)