I7 or core 2 Quad or core 2 Duo???

Whether the 3.6Ghz duo is better than a 2.66Ghz quad depends on the application in use. From my understanding AutoCAD can use about as many cores as you can provide it, and I believe Photoshop CS4 has added much better multicore support since previous versions. Sounds to me like you would benefit from having a quad core, so if I were you that is what I would get. Either a C2Q or an I7 depending on what your budget is.

ADOBE products will make use of an ATI graphics card. combine that with a p2 and you are good to go.

For AutoCad, get the i7 and a good workstation card like a Nvidia Quadro CX.

Set ups for engineers are two quad Xeons with Nvidia Quardo CX. The Intel X-25 Extreme SSD hard drives are also awesome. The i7 is basically a Xeon.

i7 since you didnt mention budget.

i7 with 12GB RAM without a doubt and given the amount of GPU and CUDA-enabled software you're using I'd get a NVIDIA Quadro CX as well.

u dont need i7. get a quad.

Your video/sound/picture editing will all hugely benefit from the extra cores.
If you have it in your budget, get a i7 with 12GB of RAM.

I don't know if either 4GB or 8GB would be better for a C2Q however.

It appears that AutoCad 08 doesn't require a large amount of RAM, so 4GB seems perfect.
However, CS4 will gobble up whatever you throw at it. So if you can get a 8BG (for C2Q, either 4x2GB or 2x4GB) or 12GB (for i7, 6x2GB [6gb sets only cost $100 anyways]) then go right for it.

What processor you have doesn't really matter for music/video watching however. Audio is fairly simple, and video relies on the GPU primarily.


Your heavy multitasking programs will gobble up all your cores.
2 cores ar 3.6GHz is essentially 7.2GHz of power. 4 cores at 2.6GHz is essentially 10.4GHz of power (not to mention the i7 has increased clock efficiency over the C2Q, placing it even more so).


A dual core with 4GB with be the cheapest, however going for a i7 and 12GB is the pimp way to go.



HOWEVER!!!
If you really want to go crazy (or me, because I'm bored), AMDs sexa core CPU (6 cores at 2GHz+) cost around $400 each. Tyan makes a quad socket mobo which supports a quad socket expansion card. The total system supports 8 CPUs and 128GB of ram. The expansion board and the motherboard could be gotten for $500-800 (if I remember correctly).
This is a combined 105.6GHz (2.2GHz x 6core x 8CPUs = 105.6GHz theoritical) power ($450 per 2.2GHz sexa core, coming in at $3,600) , with 128GB of RAM (using 32x 4GB DDR2 800MHz modules, $150 per module x32 = 4800) for another $4800.
I can't imagine what kind of PSU you would need for this, so I'll assume $500.

Now imagine, all that for only $9,500! All in one system! Would only take a high power AC to keep it reasonably cool!
($600 for mobo/expansion card, 500 for PSU, 4800 for RAM, 3600 for CPUs)

Who needs a GPU for video editing when you have that bad baby?

I would love a setup like this. If I ever hit the lotto, I will build this just to surf the internet on. But mine will have a Nvidia Quadro CX graphics card as well.

That would be awesome for FSX and media encoding, can't think of much else which can use that much processing power.

although I'd probably swap the 2.2GHz cores for 2.8GHz one's.

well like what everyone else is saying i would go and get an I7 because of the autocad and photoshop. With 4 core or 8 logical core, thanks to HT, you would get the most bang for your buck.