Core 2 duo - i think? - it has a lower spec but logically it is actally two processors so its kind of 1.86x2 - i think im right in sayin that.
Get the Core2 Duo E6300 -
It has 2 logical proccesor (two brains )
It is much newer and would be more expensive on the general market.
Because it has two logicall proccessors it can do two things better at the same time whereas the Pentium D would struggle in juggling the two around.
Im real sorry if u dont get that - basically get the core 2 duo