Faster way of writing two formulas?

Hi,

I have two array formulas

{=MAX(IF('NR1'!A:A=$A4,'NR1'!K:K))}

{=INDEX('NR1'!J:J,MATCH($A4,IF('NR1'!K:K=$X4,'NR1'!A:A),0))}

Originally these worked fine as there weren't many rows in my sheet. But now it has been expended considerably and I have them calculating in 112,000 cells (50% for one, 50% for the other) and unsurprisingly it's slowed my sheet down considerably (to a near halt!) Is there a way of re-writing these to make them run any quicker? I suspect I might have to break the sheet up, but I thought I'd check first...

Thanks!

Ah Ive just spotted there's referencing entire columns rather than the actual range. I will re-write with ranges in them. However if anyone has any suggestions feel free as I still suspect the column lookups are going to be quite large.