The CPU or Central Processing Unit is the "heart" of your computer system. All calculations, commands, requests or processes vital to running your computer or software are controlled and directed here.

In general the faster the processing speed, the faster your machine will be able to complete tasks given to it by you or the software you are running.

Some KEY technology terms before we talk about CPUs:

HT or HyperThreading
results in more efficient use of resources, higher processing throughput and improved performance with today's multi-threaded software. Especially useful for multi-tasking.

Execute Disable Bit
can prevent certain classes of malicious "buffer overflow" attacks, like worms, when combined with a supporting operating system.

Intel® Extended Memory 64 Technology
can improve performance by allowing the system to access more than 4 GB of both virtual and physical memory. Intel EM64T also provides support for 64 bit computing to help handle the applications of tomorrow.

Enhanced Intel® SpeedStep® Technology
allows the operating system to adjust the processor clock down when running applications that require less power. Increased power efficiency brings savings.

Intel® Virtualization Technology
or VT allows the user to create unique partitioned desktop environments to help keep multiple users on one PC separated and interfering with one another.

CPU Cache
is where the CPU stores recently used information by the system. The larger the cache the more information can be saved there before making room for new data. When a CPU needs to go and find information on something, its checks the cache to see it that information already exists. If it does, it simply pulls the info from that point. If not it must search elsewhere within the system to get the needed info. In essence a larger cache can increase your performance with certain types of programs.

500 Sequence
The "500" series processor is designed around Intel's® newest LGA775 socket technology. More computing power than the Celeron® series, this processor has been designed to be the mainstream solution for most users.
Supports: HT Technologies.

J Sequence
The J series processors are "500"series processors with added power saving and security features. This added security would most benefit large network environments or where and extra level of security is desired.
Supports: HT and Execution Disable Bit Technologies.

One Sequence
The "One" series processors as i like to call them, provide users with all the benefits of the "500" and "J" series with the addition of being 64bit compatible for future applications.
Supports: HT, Execution Disable Bit and EMT64 Technologies.

600 Sequence
The "600" series processors provide users with all the benefits of the "500", "J" and "One" series with the addition of an increased 2mb cache and SpeedStep® Technologies.
Supports: HT, Execution Disable Bit, EMT64 and SpeedStep® Technologies.

800 / 900Sequence
The "800" series of processors introduced a new Intel® technology, the dual core. Dual Core CPUs have two separate computing cores allowing them to receive and process two separate lines of data simultaneously. This provides quicker response times from the CPU during heavy loads compared to the "600" series.
Supports: Execution Disabled Bit, EMT64, SpeedStep® Technologies, Intel VT