A Fool and His Money: Old CPUs.

One of the hot topics always popping up in discussion, is, of course, price/performance, value, and pure performance of CPUs. People try to generalize and say AMD is always better price/performance, even if Intel is slightly better. Or people point to clock speed and number of cores, like those are the only two relevant statistics in a CPU.

Since nobody with three functional brain cells is going to say AMD can outperform Intel these days, we can skip who has pure performance. That just leaves value and price/performance comparisons. I'm going to start those two off with value.

What is value, in terms of CPU, or computer parts in general? Well, there's several categories that have to be weighed here. Performance, price, needs, additional associated costs (motherboard, PSU, etc.), and upgrade path. The additional associated costs come into this, because lets face it, it doesn't do you any good to save $20 on CPU, and pay an additional $40 on motherboard. It does make you look kind of dumb, but that's about it.

Now, only you can determine the weight of the factors in value, but it's good to think about them anyways, when considering new components. Is it worth an additional $20 to have a socket with more CPUs coming for it? Are you willing to pay 15% more for a 30% improvement? Do you actually need the 6 physical cores of that PhenomII when you're only planning to play games, most of which are optimized for 2?

While you're deciding on the subjective value of components, price/performance is pretty much guaranteed to come up. There's only one real way to handle that. You need direct comparison benchmarks for the task you want to do, assign the lower value 100%, and determine the percentage of the higher performer. Then, do the same with the prices of CPU and motherboard combined, and see whether the additional performance is a higher percentage than additional price. For example, if the Intel configuration is 25% better for your primary task, and costs 15% more than the AMD configuration, the Intel build is better price/performance.

Why do I say you have to combine motherboard price with the CPU price? Because, we're determining price/performance, and since they can't go in the same motherboard, the only logical way to compare is to combine all the factors that will be different, and compare price/performance that way.

Granted, motherboard can affect performance, depending on features, but most of the features that can really affect performance, like SATA 6Gb/s, or extra power phases to OC cost more. Once you're looking at adding to the price for raw performance, you should stop comparing price/performance, and just shoot for performance again.