Wow, I didn't notice until now but AMD has dropped their prices to insane levels

and they have also effectively killed the Core 2 Duo line in value. Their is no reason to get a Dual core now with amds low prices, their quads not only are priced at about the same as favorites like the e8400, and e8500, but even in single threaded performance they are beating or tying with the Core 2 duos, and with multithreaded performance the dual cores are being blown away. The phenom II X4. Plus if you get a Core 2 Duo, you'll be stuck on a dying platform as well. It looks like if you are going with Intel, it is i7 or bust.

Phenom II X4 955 3.2GHz vs Core 2 Duo e8500 3.16GHz


AnandTech Bench (beta): Intel Core 2 Duo E8500 vs AMD Phenom II X4 955
AnandTech Bench (beta): Intel Core 2 Duo E8400 vs AMD Phenom II X4 955


Newegg.com - Intel Core 2 Duo E8500 Wolfdale 3.16GHz 6MB L2 Cache LGA 775 65W Dual-Core Processor - Processors - Desktops
Newegg.com - AMD Phenom II X4 955 Black Edition Deneb 3.2GHz 4 x 512KB L2 Cache 6MB L3 Cache Socket AM3 125W Quad-Core Processor - Processors - Desktops

The e8500 and the Phenom II X4 955 are priced the same. As you can see in those benchmarks many things are tested from synthetic benchmarks, to 3d rendering, photoshop, gaming, video and audio encoding, compression and even file recovery. In the single threaded apps and in gaming, the Phenom II X4 performs about on par, when the e8500 does win, it is usually by a small win. But notice that when the Phenom II X4 does win, it wins big. Very big, and in games that are threaded for more than 2 cores like Grand theft Auto 4, Far Cry 2, FSX, H.A.W.X, World in Conflict, Supreme Commander, Resident Evil 5, Devil May Cry 4 and even PCSX2 software mode etc. And the many newer games that are going to be released with higher than 2 core support there will be huge boosts in performance over the e8500. Now, the e8500 can get to 4GHz easier, but I'm seeing near 4GHz overclocks on the Phenom II X4 as well. In the end 200mhz wouldn't make much of a difference in performance, once you get to the mid 3GHz you are basically good for just about everything. The extra cores however DO make huge differences and the future in gaming is going to be about using the extra cores since there isn't much more we can do with to get higher clockrates. Everyone was talking about how quadcores are useless because nothing uses quads and once we reach the future, there will be cheaper and better performing quads, well that time is now. We have the cheaper and stronger quads now and they are being taken advantage of. Intel and AMD have plans to branch out with more cores so it seems like Quad cores are the sweetspot for the mainstream gamer today. The LGA 775 line is at the end of it's like, and now it is all about AM3 and LGA 1366/LGA1156. The only reason to get a Core 2 cpu is if you are upgrading to a stronger cpu for your lga 775 motherboard. Plus the Phenom II X4 955 is a Black Edition cpu so it has an unlocked multiplier which makes it easier to overclock than it would be normally.

Here are some more match ups.

Phenom II X4 940 & 945 vs Core 2 Duo e8400


AnandTech Bench (beta): Intel Core 2 Duo E8400 vs AMD Phenom II X4 940

Newegg.com - AMD Phenom II X4 940 Deneb 3.0GHz 4 x 512KB L2 Cache 6MB L3 Cache Socket AM2+ 125W Quad-Core Black Edition Processor - Processors - Desktops
Newegg.com - AMD Phenom II X4 945 Deneb 3.0GHz 4 x 512KB L2 Cache 6MB L3 Cache Socket AM3 125W Quad-Core Processor - Processors - Desktops
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115037