If your loops are freezing mirc, optimize your code.
I have a lot of real-time adds running in my mirc and i don't notice that.

Well, belive me I got down to minimum, but try doing a simple filter with an alias on a window that has 12,000 line, and you'll see that there's nothing muchy you can aobut it...
I use a simple sort code to sort file sizes (Mb, Kb, etc..) and that takes about 20-30 secondes to process.

var %b = $calc($replace($remove($gettok($2,3,9),$chr(32),b,$chr(160)),k,* 1024,m,* (1024 ^ 2),g,* (1024 ^ 3)))
if (n isin %a) return 1
if (%b !isnum) return 1
var %a = $calc($replace($remove($gettok($1,3,9),$chr(32),b,$chr(160)),k,* 1024,m,* (1024 ^ 2),g,* (1024 ^ 3)))
if (n isin %a) return -1
if (%a !isnum) return -1
return $iif(%b > %a,-1,$iif(%a > %b,1,0))

Pretty simple code, yet necessary ... I don't think I can reduce this much...

I just want to point out that there's a problam here, and I would like to ask if it may be fixed in the next versions ?