If you're choosing between the X2 and PentiumD, the choice is pretty
easy. Particularly if you intend to build yourself.
The performance of the X2 is totally superior.
PentiumD is just trouble, and doesn't perform that great either a lot
of the time.
The retail CPU sellers hardly sell any PentiumD at all, while X2s are
all the rave. There are good reasons for that.
Dell might be able to build a tolerable PentiumD. But besides inferior
performance, the problems are heat and power consumption. I think
there might also be some question about software compatibility. At
least, I've seen that testers have failed to run some benchmarks on
the P-D.
If you take into account a lesser PSU, cheaper MB, lesser heatsink and
smaller electric bills, for the X2, the PentiumD really isn't even
cheaper.
The question is if you really should choose between X2 and P-D?
I'm always this dubious, when I see someone with an obsolete system
intending to upgrade to the latest bleeding edge screamer.
And a Gf6600 on that? Especially since your main performance
requirement will come from games? You will do just as well with a far
lesser and cheaper CPU.
Don't finance your CPU with your videocard.
Still, the 3800 X2 is a damn good CPU for its price! - No doubt about
that!
In more general terms, I also think the situation is pretty onesided
today.
My favorite Intel is the 630. Makes for a honest, value oriented
machine for video and media. With real world performance that doesn't
lag much behind the more expensive, hotter and maybe sometimes
throttling, higher clocked P4s.
Both the Celeron M and Pentium M are also pretty good for mobile
computing, but Intel lacks a 64-bit competitor for AMD's Turion 64.
- But otherwise, AMD is king right now. I don't think the difference
has ever been as large between two competing CPU manufacturers.
Especially for workstations, servers, gaming and lowend budget
desktops, the AMD advantage is pretty dramatic. I even think that if
there is a quality difference, it's in AMD's favor.
It says a lot about the market's awareness that Intel still sells as
well as they do.
Anyway, If you build a X2, you should make sure the MB bios is updated
to support the X2. You should also patch WindowsXP for dualcore, there
is a recent patch.