Intel e7400 2.8GHz vs AMD X2 6000+ 3.1GHz

I would go with the e7400 unless you just feel obliged to help the little guy. I think you'll not only get better performance but higher performance upgrades in the future.

actually, if future upgrades are a consideration, you'd be a bit better off with the amd build, just make sure you're getting a newer model am2+ motherboard. amd tends to change sockets less frequently than intel. in fact, intel probably won't be making any additional processors for the 775 socket, so you'd be limited to the current offerings for future upgrades.

if you're looking for straight-up performance now, the intel proc might be a little faster, but the difference won't be much between the two. You'd be fine either way. you won't be able to tell a difference unless you're running synthetic benchmarks

Get the e7400. I have it and it's fast. It's better than most of what amd has to offer.

This is kinda goofy.

The X2 7750 Kuma costs $25 less than the X2 6000+ (or roughly half the cost of the e7400), runs 1066MHz RAMs and is a better cpu than the 6000+. He is unloading old stock on you. It should be $60 cheaper than the e7400.

At the same price point as the e7400 your builder should be looking at the AM3 Phenom II X3 710.

http://www.newegg.com/Product/Prod [...] 6819103648

The e7400 is *much* faster. The Athlon 64 x2 is equivalent to the old Pentium D CPUs, while the e7400 is a (3rd generation?) Core2Duo, which is much faster at the same clock speed, has a much larger cache, supports the new SSE4.1 instructions, and uses less power.
As for future upgrades, that depends on how long your MB maker supplies updated BIOS's. Most older socket AM2/2+ and 775 boards can't take the latest CPUs not because they won't fit, but because the MB manufacturer has stopped producing BIOS upgrades that include support for the newest CPUs. Gigabyte and Asus currently seem to be better with this than some other makers.
Those who noted above that the "correct" peer for an e7400 is a Phenom II x3 are correct. Finally, if you are concerned about gaming performance, it's the graphics card that will make the difference, not the CPU.

Don't even compare the X2 against the Pentium D, the Pentium D was absolute garbage. According to Tom's charts an Athlon X2 4000 @2.0Ghz(Windsor) out performs the Pentium D 960 @ 3.6Ghz in Supreme Commander. Yeah the C2D are much better than the X2, but the X2 is much better than Pentium D was.

As to the OP's question, I would go with the C2D if the systems are priced similarly and have the same graphics card.