yeahhhhh my cpu is a dual core 3ghz right?
Your CPU is a dual core, but it's not like the newer dual core ones. It is lacking a lot of features of the newer ones. Below is a little info I found to help clarify. It is kind of dated, but will give you a better idea of where you stand.
One of Intel's first dual-core 64-bit Pentium CPUs. Introduced in 2005 along with the Pentium Processor Extreme Edition 840, they both share the Intel 64 64-bit technology, but the Pentium D does not include Hyper-Threading. The Pentium D's two execution cores provide two completely parallel processing streams.
The Pentium D 920 is two Pentium 4 620s put side-by-side under one metal heat spreader. The 530J will probably be roughly as fast as the D 920 in single-threaded tasks, if not edge it out by a hair. The D 920 will be faster than the 530J for multithreaded applications. The D 920 will be a little warmer than the 530J at full-load.The Core 2-based Pentium Dual Core and the Core 2 Duo are much faster than the P4 530J and PD 920. The 1.8 GHz Pentium Dual Core will outperform most every P4 and Pentium D out there, except for maybe the 3.60, 3.73, and 3.80 GHz units. It will do this while throwing off 2/3 to 1/2 as much heat as those chips as well. The Core 2 Duo E6550 is the fastest CPU on your list by quite a bit and isn't excessively expensive nor run much warmer than the Pentium Dual Core, so that's what I would spring for if you want to spend the money to get it, otherwise the Pentium Dual Core would be a good budget chip. Forget the Pentium 4 and Pentium D.