Top 10 power PCs

New Buses: Just the Ticket to Help Move Your Data Faster

For some folks, bus speed is simple--keep it above 50 mph, or the thing blows up. But for the technology-minded, bus speed is a little more complex. Very simply, a bus is the connection between the different components of a PC, such as memory and the processor.

The clock speed of a bus, expressed in millions of cycles per second (or megahertz) determines how quickly the bus sends data between the components; the faster the bus speed, the faster data flows. The bus you probably hear about most often is the frontside bus, an internal bus that connects the CPU to the memory (the backside bus connects the CPU to the Level 2 cache).

The latest version of AMD's Athlon supports a 266-MHz FSB to match the speed of 266-MHz double-data-rate memory, while Intel's Pentium 4 supports a 400-MHz FSB to communicate with fast Rambus memory. However, the FSB will run at these faster speeds only if all the other components can: Put a new Athlon into a system that supports an FSB speed of just 133 MHz, and the FSB will run at the slower speed.

The FSB is just one of the many components that contribute to a PC's speed--a faster FSB alone cannot guarantee better performance. Despite having a much faster FSB than older Pentium III systems, Pentium 4 and Rambus models have yet to show much of a speed increase in our PC WorldBench 2000 tests. But in general, increases in FSB speeds mean that FSBs create less of a bottleneck in the overall performance of a system.

Although bus speeds aren't as glamorous as CPU ratings, by taking a thorough look at your prospective new computer's specs, you can make sure that the motherboard will let you get the most out of those other high-end, high-profile components.