The I5 isn't as fast as the I7, and the I7 920 is the same price as the I5 comparable processor. A 500W supply is barely adequate for a medium end graphics card, for a high end you'd need at least 700W if not 1000.
Sorry, just didn't want you to end up with something you'd be disappointed with.
Mind you it comes with a lot more of course. The barebones packages are the most affordable. I imagine the I5 will do everything I need, but thank you just the same FL. By the way, how much faster will the I7 be than the I5?
Okay, maybe I don't need a high end graphics card.
By the way, how much faster will the I7 be than the I5?
But the only I7 starts at about twice the price.
The CPUS themselves costs about the same, around $289 (goes up and down each day practically). It's the motherboard for the I7 that costs more, it does more things and is more capable than the I5 motherboard. It also uses triple channel memory rather than dual channel.
As far as speed, it depends on what sorts of applications you plan on running. The I7 not only has 4 physical cores, but also has hyperthreading, allowing the operating system to treat each physical core as two logical processors, where your system runs as if it had 8 CPUS.
The I5 doesn't have hyperthreading, so only runs as 4 CPUS.
In certain applications, such as video encoding (if you want to edit and produce videos from a camcorder for instance), the more CPUS the faster everything runs.
In terms of upgrade paths, the I5 uses a socket which will not be supported by the newer processors coming out, whereas the I7 uses a socket which will be used by the newer processors.
As far as graphics the 8400 is practically obsolete. I'd get at least a 8800 GT, or a 9800 GT, which is a newer card and a tad bit faster.
Depends what you want the graphics card for as well. If you want to do some serious gaming with the newest games maxed out on a wide screen high def 24 inch or larger monitor, you need something like a GTX 295 or something similar (the GTX 280, 285, and 275 cards were almost as good but a LOT cheaper, but are now largely discontinued), then you're talking over $500 for the card.
If you want to play the newer games at acceptable settings on a 22 inch widescreen or smaller monitor, then the 8800GT would be fine, the 9800GT a bit better.