Hmmm...those cores have the same architecture, and the Dual is running at just over half the frequency. If the Pentium 4 has Hyper Threading, it would win out, otherwise it depends on whether you have a single or a multi threaded workload. Keep in mind both of these are total crap nowadays.
Here is another set of benches that prove that the E2140 is far superior to the P4 @ 3 Ghz. Keep in mind that in these benches, its the E2140 against a P4 that is clocked higher at 3.6 Ghz than the 3.0 Ghz you are asking about.