Xeon is for servers with server-motherboards Quad core is for desktop computers
We dont know what exact xeon you have (model, socket), so we cant anwser that.
One can purchase a Quad Xeon in many different places. Some places one can purchase it are Amazon, eBay, Best Buy, the Apple store, Staples and CPU World.
Quad Core Xeon is a brand of multi-processing microprocessors. These are targeted for the non consumer, and are mainly used and made for the business centers. The first processor was released in 1998.
The kind of processor you would expect with a PowerEdge 1950 is either Dual-Core Intel Xeon 5100, Xeon 5000 or Xeon Low Volt 5148 or Quad-Core Xeon 5300.
Apple uses a range of processors depending upon their needs these include Intel Core 2 Duo, quad-core Intel Core i5, quad-core Intel Core i7, Quad-Core Intel Xeon 3500,, Quad-Core Intel Xeon 5500 "Nehalem" processors.
2GB
The Mac Pro Desktop has a Mac Pro Desktop motherboard designed by Apple and incorporating many innovative features such as a removable tray mounting for the CPUs (Two Quad-Core Intel Xeon processors) and RAM to enable easy upgrades.
The current Mac Pro uses the Intel Xeon Quad Core processor. Earlier incarnations would have had a G5 processor.
xeon
Xeon was created in 1998.
No Xeon is a non-metal