Oookay.. i'll try to explain this.
Multitasking is a generic term for using more than 1 program at a time. Each 1ms or so the operating system let's another program has a turn. This creates the illusion of all programs running at once .
Hyper threading is a way to use wasted execution resources on a CPU. You see, up till now a CPU is only capable of handling 1 thread at a time. There's a very high chance, that this thread isn't capable of using all of the execution resources (4 interger instructions, 1 floating point instruction, and 1 SSE2/SSE/MMX instruction, per clock, for the P4.) and multhreading lets another thread execute inside the CPU to sort of absorb those processor resources.
Generally speaking, this results in more processor power, but practically speaking, it's possible for programs to contend with eachother for execution resources and the whole thing 'll bog down and you'll get ap erformance hit. Once the OS is optimised for it, hyper threading can result in a more responsive system.
Note:Hyper threading results in the creation of 2 virtual CPU's.
The reason for DP's responsivness (Dual processors, that is) is that programs that would originally monopolize a CPU and make all of the other programs sluggish, can now monopolize *1* CPU and leave the others free for other programs.
Example:Whenever the system is transfering files between HDD's and stuff, the system feels slughish
Dual processors help when: One CPU can handle all of the work related to the HDD, and the other CPU could handle other stuff.
Example: one program locks up
Dual processors help when: One CPU is at 100% usage by the program going nuts, the other CPU can handle the rest of the load of the system, resulting in virtual recovery from a situation of Doom for a single processor system
Example: You want to encode a movie, and play games at the same time
Dual processors help when:The game is offloaded to CPU 1, the encoder thread is offloaded to CPU 2
Example:Burning, websurfing, chatting, just everything you could imagine, going on at once.
Dual processors help when:They're able to spread programs across processors so that no program feels "Bogged down" due to being neglected by the CPU in light of more demanding tasks.
Basicly, hyperthreading would create another virtual CPU, allowing the benefits of Dual CPU (In a slightly less effective manner, as it *is* only 1 physical CPU) without the cost ascosciated with dual CPU's.
My question, is that you're running on a 1.7GHZ Williamette, which doesn't support hyperthreading. Chances are, your motherboard doesn't either. Are you prepared to shell out big money for a 3GHZ processor, a ne wmotherboard that supports hyprethreading etc...?
If so, i'd reccomend a granite bay board to go with it.