AMD's finest

AMD heads the race to 64-bit computing with its current line-up of processors. All of AMD's top of the line and mid-range processors contain 64-bit capabilities.

So what's the big deal with 64-bit computing? The first is the ability to support more memory then you ever dreamed possible. If you want 8GB of system memory, you can have it with the Athlon64 series. The second is 64-bit data types. By processing data 64 bits at a time, you can essentially double the amount of processing power of a 32-bit processor. The only problem is that software, including Windows, has to be coded to take advantage of the capability.

Fortunately the Athlon64 is still freakishly fast in 32-bit mode. Most of this attributable to its large 1MB L2 cache and integrated memory controller. the memory controller in most traditional PCs is handled by a separate chip called the north bridge. The north bridge chips and memory run at speeds far slower then the processor core. By attaching the north bridge to the processor directly, AMD is able to run its memory controller at the core speed, giving such systems excellent memory latency and incredible bandwidth.

Intel's Finest

Intel's flagship processor today is the Pentium4 Extreme Edition (P4EE), which has transistors that are 0.13 microns thick. This chip packs a punch thanks to a whooping 2.5MB of onboard L2 and L3 cache.

The emergence of the P4EE took many by surprise, since it was introduced shortly after Intel released an improved version of the P4 named Prescott. The revamped P4 packs new instructions for better performance in gaming and multimedia, as well as improved hyper-threading. There is also 1MB of cache vs. 512KB on the older P4.

Furthermore the new P4 is significantly more efficient in processing longs instructions. Unfortunately software must be specifically written to take advantage of all the new P4's improvements.

Fuel your need for speed

The primary spec for a processor is simple: Clock Speed. If it takes you all night to render a home movie to a DVD your authoring, or if a batch conversion of digital pictures from your digital camera takes longer then brewing a pot of coffee, then a faster processor will be just about the most valuable upgrade you can make.

Trying to decode all the Mhz madness is no easy task, however. It is entirely possible that in some applications and games a 1,000MHz slower processor can actually be faster and more powerful then the competition. When compared head to head with Intel's finest, AMD's Athlon64FX is generally considered the faster processor for gaming, despite a 1,000MHz clock speed disadvantage.

That doesn't make the trusty Pentium 4 a slow poke. In just about every office suite and MP3 encoding test, the P4 stills rules the roost.

To discover the best processor fit for you, consider your needs. If you need to perform a lot of calculations, and fast, in your daily computing, then choose an AMD processor for its floating-point advantages. If your looking to edit videos or images, then look to the Intel line-up for the best possible performance.

Terms and Lingo Explained

BGA
Ball Grid Array. This is a method of packaging a chip in which the chip is attached to the printed circuit board by means of solder instead of pins or leads. By doing so better electrical conductivity is achieved.

Clock Speed
The frequency at which a processor executes instructions. Clock speed is usually expressed in megahertz (MHz) or gigahertz (GHz).

Floating Point Instructions
Instructions that involve data with decimal points. For example 5.984 is a floating point number. The "point" is the decimal, which "floats" by changing places as the numbers being computed change.

FSB

Front-Side Bus Speed. The speed of the connection between the processor and primary system memory (RAM) on the motherboard. Front-side bus frequencies are expressed in MHz.

Gates
Transistors in a processor are also know as gates because they are essentially switches that open and close to control the flow of signals to the processor,

Hyper-threading
An Intel technology that permits the processor to execute two program threads in parallel, as if it were two separate processors in the operating system.

L1 Cache
A tiny amount for extremely fast memory used for storing instructions and/or data. L1 cache is built onto the processor itself, and information in it is immediately available to the CPU with practically no delay.

L2 Cache
Memory that stores frequently used data and instructions. When the processor cannot find the data or instructions it requires in the L1 cache, it turns to the slightly slower, but larger, L2 cache for answers. L2 cache is where the processor stores information for fast retrieval. Building L2 cache onto the processor reduces the latency (time to wait for instructions) and improves performance.

L3 Cache
After the processor looks for information in the L1 and L2 caches, it turns to the L3 cache. In comparison to the L1 and L2 caches, it takes more time to get to information in the L3 cache. Nonetheless, the L3 cache is dramatically faster then the main system memory. Not many processors include an L3 cache, but Intel's Itanium and some of its Xeon processors stand out as notable exceptions.

Micron
A metric unit equaling one millionth of a meter. One micron is about 100 times thinner then a human hair. Modern processors like the Pentium4 and Athlon64 feature wire traces that are 0.13 microns thick!

Multiplier
A function built into a processor that, when combined with a system's front-side bus, determines the processors speed. For example, and 100MHz FSB coupled with a multiplier of 8x yields a processor that runs at 800MHz.

SSE2
Streaming Single-instruction-multiple-data Extension 2. These are special instructions built into a processor that correspond with "hooks" built into software to allow for more efficient processing of multimedia tasks. Software has to be coded to take advantage of these features, and SSE2 is one example of this.

Transistor Count
The number of microscopic transistors that make up the processor chip. Modern processors typically contain tens of millions of transistors. For example, a Pentium4 is made up of 55 million transistors while the Athlon64 packs 106 million.