Buying or Upgrading a PC?

We welcome your questions on hardware and computers. The following Q&A addresses the topic of hardware upgrades for PCs and Macs, including topics such as RAM, CPU and motherboard upgrades.

Buying or upgrading a computer is, of course, one of the most challenging aspects of computing in general. Is it powerful enough? Will it become obsolete too soon? Are the components the best choices? To help you with this often-confusing task, we've prepared a glossary of common terms and some answers to common questions on what to look for when purchasing a computer or peripheral. The recommendations should be taken with a grain of salt. Just because a dealer or manufacturer's product proved suitable for our editors, doesn't mean that you will encounter the same model, price or salesperson. Our overall recommendation is: buy from a helpful dealer, based on the recommendation of a friend.

Should I Wait?

Q: I am thinking of buying a high-end PC, but it seems that a better motherboard and/or CPU design is always just around the corner. What's coming up -- and should I wait?

A: Here is our take on Intel's roadmap for the months ahead. The original Pentium chips are history and, as of Jan. 1999, we've even seen the last of the Pentium II, as Intel is moving to Pentium III designs in late February. At the high end, the Pentium III Xeon continues to be used in multiprocessing servers, although a multiple-CPU configuration of fast Pentium IIIs can usually provide comparable performance at a lower cost. The Xeon supports 2-way, 4-way and even 8-way multiprocessing, with the right motherboard and chipset. Standard Pentium II and Pentium III designs only support 2-way multiprocessing -- and the Celeron doesn't support multi-CPU configurations at all (at least officially).

The Xeon, like its Pentium Pro predecessor, requires a unique type of motherboard; the The Xeon is larger than current PII designs and requires a motherboard with a special "Slot 2" slot.  Why is the Xeon faster? The answer lies in its higher density cache and higher speed cache -- it provides full-speed level 2 cache sizes of 1 and 2 meg, compared to the Pentium II's half-speed cache of 512K.

Xeon systems have traditionally been very expensive (when they were first announced, you could buy a very nice car for the price of an 8-way multiprocessing Xeon system), but with Silicon Graphics' Jan. '99 announcement of its (already discontinued) Visual Workstation Model 540, a four-way multiprocessing-capable Xeon powerhouse with amazing graphics starting at prices under US$6000, it is safe to say that prices have plummeted. Indeed, you can now put together a dual-processor-capable Pentium III model for as little as a $1000, thanks to low-cost boards such as the (Slot 1) Legend-QDI BrillianX IV and (Socket 370) Abit BP6. Both are NT compatible. (Problems with the BrillianX and Windows 2000 have, however, been reported.)

Thus, from high to low, the Intel processor lineup looks like this: Xeon, Pentium III, Pentium II, Pentium Pro, Celeron, Pentium, 486, 386 etc. There have been numerous variants on each of these basic product families over the years; Pentiums, for example, are available in both MMX and non-MMX varieties; Pentium IIIs come in a bewildering array of models, including the new "Coppermine" versions. Celerons before the "300A" model did not include onboard cache; the newest Celerons (sometimes called Celeron II) include twice as much cache memory as the 300A and its ilk.

As well, there are Pentium-compatible chips from several companies other than Intel, including AMD, Cyrix, IBM and IDT. These hardware variations, of course, mean that not all of the chips are interchangeable, despite their software compatibility. However, the Celeron, Pentium II and Pentium III designs are all compatible (sometimes requiring an adapter) with the same BX class "Slot 1" motherboards, just as AMD K6, K6-2, Cyrix 686, and IDT WinChip processors are all compatible with the "Socket 7" motherboards designed for the earlier Pentium family of processors. Here, too, there are complications. The newest Coppermine CPUs support a faster 133MHz  bus speed than that provided by the BX chipset. For these processors, you are best off with a newer motherboard design, such as those based on the Intel i820 or VIA Pro133 chipsets. Owners of BX-compatible motherboards, however, should stick with processors that use a 100 MHz bus -- e.g., a Pentium II, PIII or (ahem) an overclocked Celeron.

The Athlon chip from AMD is yet another special case. It requires a completely different motherboard design from all the others mentioned here. It is, however, a very fast chip (available in speeds up to and beyond one gigahertz!) and is an excellent choice for those contemplating a high-end Pentium III system.

Beyond the Althon, Xeon and high-end Coppermines are Intel's unreleased processors. The immediate successor to the Coppermine is likely to be the "Willamette," which will probably be available at speeds up to 1.5 gigahertz by the time its 32-bit architecture runs out of steam.

And then there's Intel's "Merced" microprocessor. Offically known as the Itanium, this forthcoming chip is Intel's first based on a 64-bit CPU design dubbed IA ("Intel Architecture") 64 -- is likely to become available in late 2000. However, the company says it does not expect Merced to become a volume product initially -- that's a euphemism for "it will be very expensive."

But don't expect 32-bit Intel architecture designs (sometimes called "IA32") to disappear as soon as the IA64 designs show up. Even as it ramped up to release the Pentium III in Feb. 1999, Intel designers were hard at work on still another IA32 processor for release in 2000. The Pentium III, with its support for 70 new instructions designed to boost the performance of 2D and 3D graphics (e.g., games!), has already been boosted to speeds as fast as 1GHz and may sport a 200-MHz bus by the time it, too, is inevitably retired.

At the low end, Intel today uses the Celeron and motherboards based on the EX chipset. Many 1998-era midrange Pentium II machines used the LX chipset, with its 66 MHz bus, but these machines will not be upgradeable to the Pentium III without a motherboard replacement. Fortunately, PC owners who purchased a machine with a so-called BX motherboard, available since Q2'98, are able to simply drop a Pentium III into the system's Slot 1 single edge connector. The BX motherboards and “Deschutes” Pentium II chips designed for the 100 MHz bus can also be used with Celeron chips, further adding to their versatility. Complicated, isn’t it?

Surprisingly, the Pentium-class chip has proven to have an extended life in the portable market, as numerous Pentium- and AMD K6-based laptops are still on the market, primarily based on Intel's “Tillamook” mobile Pentium design.

Meanwhile, mobile Pentium II designs also emerged during 1998, and were refreshed by with new Pentium II designs carrying 256K of on-board cache in 1999. Other new mobile Celeron designs, similar to the "Tillamook" mobile version of the Pentium II processor minicartridge released in Q3'98 subsequently improved the design further: they were 1/6 the volume and 1/4 the weight of the original Pentium II. These new chips, in addition to their higher performance, reduced the high power drain that impacted battery life on older models. These new mobile chips appeared in a number of new portable computers, such as the HP OmniBook 900. And then, in 2000, Intel released a further refinement: a version of the Pentium III for the mobile market that featured a power management function dubbed "Speedstep." This feature made portables based on this PIII model the most energy-efficient ever.