4 things you must know about PC chips

By Kim Komando

How's this for clarity? "Athlon 64-bit, 3200+, 2.0 GHz, 1 MB L2 cache."

Yes, folks, the economy is getting better, your PCs are getting older, and it's time to think about getting new ones.

But that means you'll once more have to wade through a thicket of obtuse terms like the above. Is it any wonder that people throw themselves into the arms of salespeople?

Intuitively, you know that's not a good idea. The description above is for the microprocessor, usually the most expensive component in the computer. It's also the most confusing.

So let's see if we can clear up some of that fog. Here are four things you need to know about microprocessors.

1. Don't worry about bits.

That applies to the "64-bit" reference in the first paragraph. The Athlon 64 chip is made by AMD (Advanced Micro Devices), and it is very advanced, indeed. In fact, it is so advanced that there is no software to run it, yet.

The "64-bit" refers to the chip's potential ability to handle 64 bits of data at a time. Other chips handle just 32 bits. But there is no Windows version available for the Athlon 64. This chip runs today's software, because it also can crunch 32 bits at a time. It's sort of a dual chip. It can handle today's software and will be ready for the future.

Apple also has 64-bit chips in its PowerMac G5. It uses the OS X Panther operating system, which Apple has tweaked for the 64-bit chip. I wouldn't put a lot of stock in that. Operating systems need to be completely rewritten for 64 bits. Apple's chips can also run 32-bit software handily.

Make no mistake -- 64-bit computing is the future.

2. Don't worry about clock speed.

Traditionally, computers have been sold based on the microprocessor's chip. People intuitively understood that a 100 megahertz chip was better than one running at 66 megahertz. For many years, Intel pushed speeds up relentlessly.

But clock speed is only one indicator of quality. Chips manufactured by AMD and Apple run at much lower clock speeds. But in many cases, they work faster than those made by Intel.

That's because the internal structure of chips is as important as speed. AMD, Motorola and IBM (the latter two supply Apple's chips) have long concentrated on the internals. Published tests consistently show AMD's chips slightly outrunning those made by Intel. Apple's chips also beat Intel's in some tests.

Are Intel's chips slow? No. As a matter of fact, they're very powerful. The differences between brands usually aren't significant in the real world.

So, when you hit the store, a salesperson may point out that an Intel-equipped machine runs at 3 GHz, while an AMD machine runs at "only" 2.0 GHz. That AMD machine may be faster. In this case, the AMD chip will have a designation such as 3000+. That's AMD's way of showing that its chip is approximately comparable to the Intel 3.06 GHz.

3. L2 cache is relatively important.

L2 stands for "level two." This is a bank of memory that is built onto the chip, or is located near the chip. It contains commands. If your next command corresponds with one in L2 cache, the chip can move faster. If not, it must go to random access memory (RAM), the main system memory. That will take longer.

Obviously, the larger L2 cache is, the more commands will be stored there. And the more commands that are stored, the more likely that the chip can find what it needs.

Higher-end 32-bit chips made by Intel and AMD have 512 kilobytes of L2 cache. Apple's 64-bit chips also have 512 kilobytes. The AMD 64-bit chips have twice as much--1 megabyte.

YSo is L2 cache really important? The answer is yes if you're doing stuff that taxes the microprocessor. For instance, photo and video editing are demanding. So are many games.

But if you run regular office programs and surf the Web, L2 cache is less important. In fact, I'm writing this on a machine that has an Intel Celeron. This budget chip has just 128 KB of L2 cache. It does just fine.

4. Microprocessors aren't as important as you might think.

That's a huge generalization. The aforementioned gamers need lots of power, as do video editors. But most of us work on business documents and mess around on the Web. Big power just isn't necessary.

That said, you can often find powerful chips at bargain prices. Those are machines running AMD Athlon XP chips. These microprocessors are comparable to Intel Pentium 4s, but usually much cheaper. In fact, their prices are closer to the Celeron's. But the Athlon XP runs circles around the Celeron.

Fact is, there was a time when software really taxed microprocessors. Those constant increases in speed were needed. But that is not the case today. Microprocessors generally have more power than the software requires. On the top end, they have a lot more.

If you fall into the office-documents-and-Web-surfing group, practically any microprocessor will do. If you're on a budget (and who is not?), save on the chip and buy extra RAM. Better yet, take your spouse to dinner. Now, that can pay dividends!