Hi Tigger,
since you want a more detailed anwser than "conroe blows it away" ill give it a try.
First, you cant compare dual core directly to single core performance wise. So i will first assume you only use one of the cores in the conroe.
1.) power : core2duo BOTH cores together use 65W, prescott ONE core uses 100W. If you only use one of the two cores, that uses more than 50% since it uses the whole cache, thats like 40W against 100W. Since you often have the comp swithced on but dont need the cpu for more than 10% of its power and conroe is much better in power saving its probably more like 25W to 80W.
2.) Raw numbers: 1 conroe core does more than 3 times the work of one prescott at the same frequency. Since the rest of the computer is virtually the same, the conroe computer is slowed and does about 2.2 times as much only, the whole computer. That is for a 1.83G Conroe you need at least a 4G Prescott, which doesnt exist. If you overclock your prescott to that level it uses 130W, has a shortend livespan and you still have only 1 core. Still you pit it against a stock conroe which could be overclocked as well, running at performance the prescott never reaches.
3.) Application performance: Compare some numbers on the net, checking the 2 cpu prescott version against the conroe 2 duo, the conroe 1.83 gives about the same performance as the D 960 clocked to 3.9G, slightly better in single threaded apps. It is a lot better in apps that use both cores, since it has a much better dual core design than the pentium D. prescott runs worse than the 8xx /9xx dual cpus.
4.) Conroe 1.83 against prescott 3.2: ONE core is about 1.25 times as fast. Then you have a second core, which can give up to 80% improovement in one app and can give 90% for other work when you do multitasking. Now comes the hard part, usually i do not run 2 full apps but require responsiveness, harddisk, networking, security, gui etc. where i would say the second core adds about 60% of its usefullnes.
That would be total 2 times the performance in the core 2 system.
4.) Efficiency: Take halve power by double performance land at 4x. I am cheating here since the total power consumption of the computer is far less than double, but looking at the cpu that is what it gives. The advantage of using low power is more than just the reduced power, less noise, less cooling trouble, less dust trouble and longer live (for the computer only).
To be short, that is like driving with a 20 year old, no airbag, no impact protection, no abs, loud car that does halve the mgp or with a new, airbag, abs, efficient, more comfortable and faster car that does double the mpg. Now sadly modern cars arent that much better than old ones, and arent aloud to drive at 130mph instead of 65mph. Not talking about they wouldnt be able to do that with using halve the fuel. But probably with halve the maintenance cost.
Or, much shorter: The conroe blows the prescott away, by far. Its better than A64 x2, its better than D9xx / D8xx but ill save you the details. Still, with the dropped prices of the a64 x2 and the EE versions amd gained ground and is no longer that far behind.
Of course, if you put in a budget constrained where core 2 duo is simply to expensive or a home pc with no gaming / other cpu intensive stuff in mind the world looks diffrent and an AMD 3600EE might get intresting. But thats a moot point on a board for AH2 pilots.
