Microprocessor mayhem....

Geek Alert: This post is intended to be read by PC hardware enthusiasts only. Proceed at your own risk.

Yeah, this is another geek post, but I just couldn't help it. Lately it seems as if someone is always asking me a question in relation to this. Despite being quite ubiquitous nowadays, it would seem that the inner workings of PCs still remain a mystery to most people.

I've built a lot of PCs for other people (like here for example) and I've answered a lot of queries on this topic this from my friends and colleagues. From what I have heard other people say, there are just a lot of false notions and misconceptions when it comes to devices at the heart of every PC - the CPU, or simply the processor.

Well, the aim of this post is to try and clear up those misconceptions. Hopefully, someone out there would find this information useful.

Here are some of the most common questions that people seem to ask me, as well as replies phrased as simple as I can make them:

What kind of processor should I buy?

Simply put, if you're into heavy stuff like 3D gaming, video or audio encoding, source code compiling, computer aided design, etc., get yourself a mid to high-end processor. If you just surf the internet, chat, use Microsoft Office applications, play MP3s or video files, you can get by using a low-end processor.

Mid to high-end processors include the Intel Pentium 4 and Pentium 4 Extreme Edition and AMD's Athlon 64 (Socket 754 and Socket 939 versions) and Athlon 64 FX. Low end processors include the Intel Celeron (Celeron and Celeron D) and the AMD Sempron (Socket A and Socket 754 versions).

Should I go Intel or AMD?

For the most part, any of these processors should be fast enough for you. There are similarities and differences with Intel's and AMD's processors, but if you have to ask, it probably means that you would be happy with either.

Are AMD processors reliable?

Yup. I've never encountered a processor, Intel or AMD, which actually broke down. I've seen a few processors which burned up after the heat sink fan died, or had a cracked die from faulty heat sink installation, or a broken or bent pin, or just plain died from electrostatic discharge (static electricity) due to mishandling. I've never seen any processor fail once properly installed, provided the fan works. (Note: Never skimp on the fan. Always use a high quality ball-bearing fan.) Whether you go Intel or AMD, its very likely that the processor will last for years and years. You'll be more likely to replace it from obsolescence rather than because of a breakdown.

Which processors are faster? Intel's, or AMD's?

Typically, the gigahertz rating of Intel processors are more or less equivalent to the model numbers on AMD processors. For example, a 3.0 GHz Intel Pentium 4 should be, more or less, equal to an Athlon 64 3000+ in performance. This comparison is usually enough for most people. Of course, it is worth noting that the Pentium 4 and the Athlon 64 have very different internal designs. While the Pentium 4 in our example runs at 3.0 GHz, the Athlon 64 needs to run at only 2.0 GHz to come up with matching performance.

If you want to know what the fastest processor currently available is, it's probably the AMD Athlon 64 FX (see this article on ExtremeTech). Of course, the Intel Pentium 4 Extreme Edition isn't far behind, and is even faster in some tests. Take note that the latest Athlon 64 FX (the FX-57) runs at only 2.8 GHz, yet it matches, and for the most part even exceeds the performance of the Pentium 4 Extreme Edition which runs at 3.8 GHz, or a full gigahertz faster.

It is important to remember that more gigahertz does not necessarily correspond to better performance, especially among different processors.

How about Intel's and AMD's low end processors?

Intel's current low-end line of processors is the Celeron D. AMD's low-end line consists of the Sempron processor. The Sempron processor comes in two-flavors, a Socket A version (the Socket A is an older processor interface, compatible with the defunct Athlon and Athlon XP lines) and a Socket 754 version (a more current processor interface, compatible with the Athlon 64).

While the Socket A Sempron soundly trounced the older version of the Celeron (based on the Williamette core), the current Celeron D seems to perform slightly faster. Maybe not enough to be noticeable, but enough to beat the Socket A Sempron by 5-6% using real-world benchmarks.

Or course, the Socket 754 version of the Sempron simply runs rings around the Socket A Sempron and the Celeron D.

What about cost?

AMD's processors are usually less expensive (sometimes significantly so) than their Intel counterparts. Even motherboards for AMD processors are cheaper than those for Intel processors. Considering the performance of AMD processors which range from being slightly slower to being significantly faster than Intel processors, I'm often inclined towards AMD's offerings rather than Intel's for the simple reason that they offer more bang for the buck.

Are Intel processors and AMD processors compatible?

From a physical point of view, the answer is no. They use different processor sockets, and they are not interchangeable.

From a software point of view, yes. There are some differences in their implementation (or lack thereof) of multithreading and certain instructions sets, particularly regarding multimedia and 64-bit extensions, but yes, they run the same software. It's probably worth knowing that all Athlon 64s and some Semprons have support for 64-bit software. Not all Pentium 4s support 64-bit software, though some models do. Do your research or ask first before buying, if 64-bit functionality is important to you. And it probably should, since 64-bit operating systems are soon to go mainstream.

I've heard AMD processors run hotter.

That used to be true, though it really was a non-issue provided you install a well-built heat sink and fan combination. Let me make it even simpler for you. Nowadays, all processors, especially the higher performing ones, whether made by Intel or AMD, run hot.

So what do you recommend?

With the performance and reliability of all current processors, you can't go wrong with whatever processor you choose. When budget becomes a factor, and if you're in the know, you would probably gravitate towards AMD processors. If you don't really care about how much you spend, or if you're unfamiliar with AMD, you'd probably go to Intel, if anything else because of brand recognition.

However, if it were me, I'd get an Athlon 64 (mid to high-end) or a Socket 754 Sempron (low-end) based PC. These are just as fast, or even faster than their Intel equivalents. They are also cheaper.

Does that mean the Pentium 4, the Celeron D and Socket A Semprons suck?

Not at all. The Pentium 4 is a very powerful processor. It's just expensive, and the top models can eat up a lot of electrical power (it's also slower than the Athlon 64 when running 64-bit software, but that doesn't really matter at this point in time). If you can afford a Pentium 4, why not?

As for the low-end, the Celeron D has all the functionality of a late model Pentium IV, despite having a slightly slower front-side bus speed (the speed with which the motherboard talks to the processor), less L2 cache (a temporary holding area of frequently accessed data built in the processor) and lack of Hyper-Threading (ability to simulate more than one physical processor). The Socket A Sempron, on the other hand, is based on the Athlon XP, AMD's previous flagship processor. Unless you have extreme processing requirements (very few people really do), any of these low-end processors will suit you just fine.

What processor do you use now?

I'm still using An Athlon XP based computer, specifically an Athlon XP 2400+ (see my current specs here). This processor line has already been discontinued by AMD, but the processor core (known as the Thoroughbred-B core) lives on as the Socket A version of the Sempron. No plans to upgrade as of yet. It's still plenty fast for what I use my PC for. But I already foresee an Athlon 64 somewhere in my future. :-)

I hope you find this post informative and helpful. Please feel free to ask questions if there's anything else you people would like to know. Comments are welcome too.