Match data in 1 column and count unique data in another column based on matches

Hello,

I was curious if anyone would have an alternate formula to use to match data in one column and count unique data in another column that wouldn't require an Array? I found the array formula below and it works, but my worksheet has 60,000 rows and this formula takes forever to calculate, which makes it impossible to use. I was hoping for an alternative formula that may not require as much computer resources and could provide the results in a timely fashion. Appreciate any suggestions/alternative formulas!

Array formula:

=SUMPRODUCT((($A$3:$A$40000=A3))/COUNTIFS($A$3:$A$40000,$A$3:$A$40000&"",$B$3:$B$40000,$B$3:$B$40000&""))