PC Processor Primer cont..

Speeds (in MHz): With cache: 300, 333; without cache: 266, 300
What you'll pay: Less than $2,500 for a PC with a Celeron-333, 64MB of RAM, and a 6.4GB hard disk.
What you'll get: If you buy a Celeron with cache, you'll get a cheap PC with plenty of power.

Celeron is Intel's cost-conscious version of the Pentium II. The Celeron is based on the same core technology, but it's targeted at the lower end of the PC market. There are two versions of the Celeron: one with secondary cache memory, one without. Celeron was originally introduced without cache, at 266 MHz and 300 MHz, and was a disappointing performer. Systems carrying this CPU lagged behind the fastest Pentium MMX chips in some testing situations, as well as behind chips from AMD and Cyrix.

More recently, Intel introduced new 300- and 333-MHz Celeron chips, code-named Mendocino. The new Celerons include 128K of integrated secondary cache. (as compared to Pentium II-based systems which carry 512K) In the Celeron's case, a little cache goes a long way. The Celeron integrated cache runs at full processor speed, as opposed to the Pentium II's cache, which runs at only one-half the processor speed. The end result is that for standard productivity applications, Celeron processors running at slower speeds than PIIs show an almost negligible performance lag, largely thanks to the speedy secondary cache.

You probably don't want to buy a Celeron without cache, and it looks as though few vendors will even give you the chance--most offer only the cache version. If you're looking for a machine that doesn't have a lot of frills but is fast and affordable, the Celeron is a good pick.

AMD-K6-2

Speeds (in MHz): 300, 333, 350, 366, 380, 400
What you'll pay: The K6-2 muscles most CPUs out of the way in the under-$1,500 PC space.
What you'll get: Excellent performance for the money and 3DNow technology.

With the K6-2, AMD stakes its place as an innovator. The K6-2 introduces 3DNow technology, a set of 21 processor instructions designed to accelerate 3D performance the same way that the MMX instruction set accelerates multimedia. But unlike MMX, software does not have to be written specifically for 3DNow to benefit; titles written for DirectX 6 and OpenGL will also be enhanced.

AMD touched up the processor to provide better performance on general applications and added support for a 100-MHz system bus. The K6-2 now tops out at 400 MHz, just one clock speed behind Intel's 450-MHz Pentium II. The Pentium II still stands as the performance leader, outpacing the K6-2 in most of our applications-based testing at the same clock speed. But the K6-2 is no slouch.

And what happened to the original K6? You'll find machines out there that still use K6, but unless they have an incredibly low price, you'll probably want to stay away. K6 is out, K6-2 is in. If you want a low-cost PC, the K6-2 offers a great amount of power for the price.

Cyrix M II (formerly 6x86MX)

Speeds (in MHz): 266, 300, 333
What you'll pay: The M II shows up in PCs that cost less than $1,500.
What you'll get: Not the best game-playing performance but enough power for word processing, spreadsheets, and Web surfing.

Cyrix renamed its 6x86MX the M II to position the processor directly against Intel's Pentium II. However, these two CPUs are not exactly equivalent. Cyrix has tried to stack the M II 300 MHz against Intel's Pentium II 300 MHz, but the M II-300 actually runs at 233 MHz. With 64K of internal cache memory (double the 32K found in the Pentium II) and support for MMX, the M II still does well--but not that well. Our tests have shown that the M II-300 is much closer to the PII-266 when running productivity applications.

Overall, the M II (and the older 6x86MX) makes a strong price-performance choice, but the processor lacks a little oomph when it comes to floating-point-intense applications such as 3D games--an effect of the lower actual clock speed. Still, if your computing tasks consist of word processing and spreadsheets rather than the dungeons of Quake, the M II will provide you with more than enough power--and at a price you can afford. But in our testing of low-cost PCs, we've found that you'll get even more bang for your buck if you go with AMD's K6-2.

Cyrix MediaGX

Speed (in MHz): 233
What you'll pay: Less than $750 for complete PCs.
What you'll get: The lowest-price PC or laptop around, but the chip's performance lags.

Cyrix takes a different approach to affordable computing with the MediaGX. The CPU integrates graphics, audio, memory control, and PCI interface, a design often referred to as a system on a chip. This architecture eliminates the need for each component to be separate, thus effectively lowering the total system cost. To further reduce costs, the MediaGX allocates some of the system memory for video memory.

The MediaGX now clocks in at a top speed of 233 MHz and includes support for MMX, yet complete systems based on this part come in at less than $1000, including a monitor. Although the MediaGX seems great from a cost perspective, performance isn't quite as encouraging. It's adequate for basic computing chores such as word processing, email, and Web browsing, but this CPU lacks the raw muscle for more demanding tasks. It also omits 3D hardware acceleration for games, which is important since the processor, not an add-in card, handles graphics.