I just got a p4 2.4c with ht...
my question is since games don't use both processors will the game be running at 1.2ghz??
whats the deal?
No the game will not run at 1200MHz. HyperThreading splits the processor into two cores. One physical and the second a logical core, the first core is slightly faster than the second core however
Some games have multi-threaded support but there are few. When you run an application that only executes one thread per clock cycle the thread will execute on both cores (not shared equally). However this will lower performance as they are built to execute a thread each not share one. This reduce performance somewhere near 25% on average (changes depending on the application), thus your only getting 75% of your CPU's processing power.
You may have heard that Intel processors process six operations per clock cycle. Now if we use that as an example we could say that each core does three each, however that can change as the opps are not shared equally.
I will not go into the details here (if you want to see more see the HT FAQ). Lets just say that the application will run a little bit slower with HT on than off most likely, to be honest I would experiment and see what setting works better (on or off).