What Determines a Computer's Speed?

The 'speed' of a computer is, for the most part, undetermined. Popular methods for determining speed include the clock speed of the processor, how many floating operations per second (flops), frames per second on video rendering, and other benchmarks. But, no one can seem to agree on one universal standard for 'speed' in the computing world. That's because there really isn't one universal benchmark for speed. For science and heavily based math applications, flops seems to reign due to flops being one of the more expensive and slow operations on a computer, others being video rendering and factoring.

The clock speed of a processor is how most people determine how fast their computer is. Clock speed is important, because everything in a computer has to be done on a clock boundary (either the rising or falling edge of the clock, or in some cases (Intel core i7)) both. So, if your processor has a clock speed of 3.2 GHz (pronounced 3.2 gigahertz(hertz is the SI measurement for cycles per second, most frequently used in waves)) your computer can technically do 3.2 billion operations per second. That's on a basic level, not taking into account hyper-threading(HT), multi-core processors, instruction level pipelining(ILP), the general quality of the architecture, and the implementation of the Arithmetic Logic Unit(s)(ALU). What used to take 20 clock cycles on older computers (division namely) now takes fractions of a clock cycle. So as you can see, there are many other factors to consider instead of just clock speed.

FLOPS is another popular method of measuring speed, but it is also not a definitive test for speed in the penultimate test. The FLOPS measurement is usually used for performance of supercomputers (computers built for insanely large calculations usually used by scientists). The FLOPS measurement, while more accurate than clock speed for sure, still falls short because it fails to represent anything other than mathematical computations, and only a small subset of them at that. Although everything in a computer IS based on math, the FLOPS measurement does not really represent actual speed because of varying costs of different floating point operations themselves, and the complexity of modern-day applications.

So, how do we define 'speed' in the computer realm? Put short, there really is no unified method. One could look at a huge spreadsheet of benchmarks (3DMark, Windows Vista Experience Rating) and kinda figure out which one is best for what you need it for. For example, some computers perform great in graphics due to multiple Graphical Processing Units(GPUs), but fall short in other areas because of other things not being the same quality. Another computer might be great at gaming but take forever to zip a file. The best way to get a decent overall rating of the speed of a computer is to look at 3 things (which also happen to be the main bottlenecks of the whole computing experience):

1. Quality of RAM. DDR1 RAM isn't going to cut it any more. Upgrade to DDR2-3.

2. Amount of RAM. Get at least 4GB.

3. New-ness of processor. Processors are getting exponentially more powerful as time goes on (Moore's Law). A Celeron processor from 2000 isn't going to perform nearly as well as a same-costing processor from 2009

Hopefully this article helped you understand more about your computer and just what 'speed' is.