Im aware theres a ton of info and threads on Dual core vs Quad core and its probably due to this thats adding to my confusion. Also I spent a while last night arguing which a friend over the pro's and cons. Also all the threads I read seem to be people with quads saying they're great... and the people with duals saying you dont need a quad.
Hes saying I wont need quad, Im thinking I do... I know it comes down to what your going to use it for.

Im building a system, and I have the obvious dilema of using one of these two CPU's. (cant be bothered to wait for nehlam & X58)

Intel Core 2 Quad Q9550 2.83GHz 12M Cache S775 1333MHZ £352.99 (clocked a little on water, I understand you cant clock this chip much)
Or
Intel Core 2 Duo E8500 3.16GHz 6MB Cache S775 1333MHZ £123.36 (clocked up high on water)

The machines going to be used for: -
1) 3D games development which entails the following...
- Heavy use of Visual Studio 2008 and running 3D apps in debug mode (both on windows and remotely to 360)
- Heavy use of 3D Studio Max 2008
- Heavy use of Adobe photoshop
- Heavy use of ATI developer tools

2) Playing games for fun crysis etc but more Dev work than playing if Im honest.
3) Small amount of video edting
4) Ripping music and DVDs to put onto my HTPC
5) general email, surfing etc etc but I usually muti-task large apps like PS and Max

Now I know theres not much support for quads in present games, so for that purpous I could make do with a dual core.
But I know that Photoshop and 3DS Max do benefit greatly from using a Quad! Same as vid editing but I dont do much of that so no biggy there.
Also being a programmer as well as being a handy 3D artist I guess I would like to start coding with quad support in mind (Multi-threaded Asynchronous Programming). Makes sense if you have the hardware.... use it!
Price isn't an issue for me but I dont want to waste money (could spent it in other areas) and there is a big difference between these CPU's...

I think Ive answered my own question but I'd like to hear some oppinions.

Quad Core......period.

That is your best bet for any kind of 3D development. Yes GPU's are important...but a Quad you will see the benefit from.

Dual Core would work, but at least with the Quad, theres a bit of future with it.

Again, with all the information out there, proper research (which you obviously have done), you have answered your own questions.

Cheers,

-PM

Yes, you answered your own question. If you can utilize the additional cores then the quad is the obvious choice. OC'd above 3.2-3.4ghz, the quads gaming performance will be more than adequate to generally make the faster performance of a higher clocked dual a mute point and for bragging rights only. I am not sure I would go with the water cooling on either chips as they run rather cool overall and put the money into better mobo(P45 - good for high FSB with quads) and graphics solution. Those two things will help with OC and performance.

+1 for Quad

The quad core will give you much better performance.
100% for the quad.

While it probably can not overclock as far as an E8500, with proper cooling, you should have no problem taking it to 3.4Ghz and probably further.

Cool! Awesome quick replies. I think you've settled my argument.
I know I can achieve everything I want on either chip, I can still code for muti cores on a dual, and all my other software will run quite happily on either.
But I guess what Ive been reading is from people with pure gaming rig's saying quads are overkill but since I can actually use a quad properly I was leaning towards one

I think Im going to go for an Asus P5E3 PREMIUM X48 probably with 8gb DDR-3 1600mhz
I just cant justify the cost of the quad core extreme chips they're double the price of the Q9550 even though they'll overclock more its just not worth it imo.

The watercooling's coming with the case Ive fallen in love with, Thermaltake Kandalf LCS so may as well use it lol but I know its not strictly needed.
Graphics will be the ATI 4870x2

Quad core ++ It will save you time compared to dual core. I rly want to see some benchmarks on the x2!

Quad Core, but the Q9550 is due for a Price Drop on Aug 10th.
Forget Water Cooling.
It's nice for Show, but really not worth the price or hassle.

You will be far better served spending your money elsewhere.

Agreed, both CPUs will fare well in any game especially overclocked (however slightly), so your main goal will be to optimize for your game development. You'll see a nearly linear scale between a dual and a quad-core in those apps which means you'll gain nearly 2x the performance from a quad at the same clock speed. That in itself makes the quad-core more than the best decision.

As far as gaming goes, the quad will be able to process background tasks while you play a game that supports dual-core which can increase performance over a dual-core if you have a few other things running at the same time.

from the list of stuff u said. i quad seems the right option.

Yeah thats what Im thinking because you write some code in visual studio, build then run the app while VS is chugging away in the background watching it, so Im thinking the quad would be far better in that situation.

Also since software is lagging behind hardware at the moment I really want to start coding for multi CPU's since it makes perfect sense to have one core for rendering and working with the GPU, one core for physics, another input, sound etc etc

And the dev tools I use already support quads.

yep the X2 should be smoking its the only thing holding up my build... 9 days to go!!!

Just get 2 dual core CPU's... that way you have a dual, or 2 for a quad... . o O (Oh.. NM)