So yes the Intel Xeon 3060 would outperform the Intel Pentium® D 915 by a good bit.
Thanks for the answer and the link (I've used the comparison function to compare the two processors side by side).
I found the following benchmarks (Passmark). They say that the Xeon 3060 is 1.9 times faster than the Pentium D 915... Is that even possible? The 3060 has a passmark score of 1430 and the Pentium D 915 has a score of 741.
The whole CPU list : http://www.cpubenchmark.net/cpu_list.php
Xeon 3060 score : http://www.cpubenchmark.net/cpu_lookup.php?cpu=Intel+Xeon+3060+%40+2.40GHz
Pentium D 915 score : http://www.cpubenchmark.net/cpu_lookup.php?cpu=Intel+Pentium+D+2.80GHz
Does it look realistic?