could you list any examples of multi-thread enviorments. Are they mostly geared toward workstation apps like Photoshop and 3dMax or do game writers implement it too?
Well, yes and no.
Workstations apps are, at the moment, those who make the best usage of dual-cores, but that isn't the only type of multi-threaded enviroment you come across. You also get multiple threads if you run several single-threaded apps at once. So if you for some reason have something eating processor in the background while gaming, dual-core definitely helps. (Something a more demanding than a resident AV and firewall, that is.) If my weekly AV scan starts while I'm gaming I won't notice it, but a buddy of mine with a single-core screams bloody murder every time.
As for gaming and dual-cores
, that is a hot topic at the moment.
The reality as of now: You will, with most games out now and most games coming out this year loose a lot of performance in getting the Athlon 64 X2 3800+ instead of the Athlon 64 3800+. BUT...
(you knew it was coming)
There are a few games out that are multi-threaded. There was a patch released for Quake 4 that made it multi-threaded (gave me a 35% performance boost). This probably means that any future games released on the Doom3 engine will be multi-threaded.
Then there is Unreal Engine 3, which is heavily multi-threaded. There are about 30 games announced for UE3, with probably even more yet unannounced. But most of them are still far of, without even a official name yet (ie Splinter Cell 5). The first will probably be Unreal Tournament 2007 which probably will be out for Christmas.
Another thing is Windows Vista. It will be multi-threaded, and this will be a big bonus for games. DirectX9, despite the fact that most games use it, isn't all that impressive. It is inefficient with a lot of overhead. With Vistas multi-threadedness it can offload this overhead to the other core, which will give all DX9 games a boost. Conclusion?
If you weren't going to upgrade the CPU for the next 4 years the you would have to go dual-core to future-proof your computer. Or if you're going to jump on the Vista bandwagon the moment it comes out, getting dual-core is also a good idea, but the it would pay to wait for DDR2 as Vista is supposed to be a memory bandwidth-hog. AMD will go over to DDR2 with the AM2 socket which comes out 6.6.06 (clear sign they got something demonic planned, yes?
Since you plan to upgrade the processor getting a dual-core would be a waste of money, since you would have to jump all the way up to the Athlon 64 X2 4600+ to get Athlon 64 3800+ level gaming performance.