Probably old news but, from an interview with Gabe Newell:
"Will Half-Life 2 have any special optimizations for 64-bit processors?
Gabe Newell: I would expect we would run about 30% faster clock for clock comparing an Athlon running 32-bit code and an Athlon 64 running 64-bit code. Release of the 64-bit client will be gated on MS releasing 64-bit Windows."
http://www.halflife2.net/article_valvespeak_1.php
If this is any indication of the average speedboost that can be achieved in games with 64-bit I'm gonna get me an A64 ASAP
Now if only MS would get of their asses =[
"Will Half-Life 2 have any special optimizations for 64-bit processors?
Gabe Newell: I would expect we would run about 30% faster clock for clock comparing an Athlon running 32-bit code and an Athlon 64 running 64-bit code. Release of the 64-bit client will be gated on MS releasing 64-bit Windows."
http://www.halflife2.net/article_valvespeak_1.php
If this is any indication of the average speedboost that can be achieved in games with 64-bit I'm gonna get me an A64 ASAP
Now if only MS would get of their asses =[