Hi -
Awesome - this tells you lots of good info.
1. You have a socket socket 775, so any CPU upgrade will have to be compatible with this.
2. Type "Pentium D" into Google (or your favorite search engine) and you'll find that good references for this line of processor, including this Wikipedia article
http://en.wikipedia.org/wiki/Pentium_D
2.1 Your're currently running at 3.0 GHz. From the Wikipedia article, you'll see that the Pentium D has versions running up to 3.6 GHz.
2.2 Yes, this is a dual-core processor, but based on an older architecture.
3. You're currently running at 3.0 Ghz. If you go to Amazon and type in "Pentium D" you'll see a number of second-hand processors up to the 3.6 GHz model on sale from second-hand vendors.
So this is all very interesting, but what does it mean? Well, you've got a little bit of room to upgrade (3GHz to 3.6) for a slight improvement in CPU, but overall, this is a very old PC. Your MOBO probably supports a maximum of 2GB may or may not have a SATA-1 interface (SATA-3 is current) and likely only supports the older/slower PCIe interfaces.
What is it that you want to do, what are you trying to accomplish with this upgrade? It may be a case of "you can't get there from here."
FYI, I have a similar old machine. I use it primarily as a backup server for the house and a few older games that I just can't live without. But that's about it.
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