Threads max out at 65535. Last post is 65534. I should know, I'm one of two people in FR history, that I am aware of, to get one.
100k is impossible unless they recompile the thread code for 64-bit addressing on a Win 2003 Ad Serv 64-bit Opteron server.
Well then go do and come back and tell us when it is done Dead Corpse in a Bunny Suit Man.