Comparing 2 grids

Question

I have 2 datagrids in my form and each of them has over 8000 rows. There is only 1 common column which is numeric. And I want to compare those 2 grids via this numeric colum. There are 6 columns to be compared. What would be the fastest way to do it? I tried to filter 2nd grid for each row in 1st grid, it does what I wanna do but very slow. It takes like 5 mins. I wanna be able to do it much faster, like within 2 mins if it's possible.

Thanks in advance.