April 20, 1998
New Pentium IIs put an end to processor upgrades
By Bob O'Donnell
One of the great things about personal computers is that you're never really stuck with
what you buy -- you can always upgrade the system as your needs increase. This in fact has
been one of the defining characteristics of the PC. It's also been pretty darn handy given
that Moore's Law shows no signs of slowing down, hardware requirements continue to
increase, and people are trying to make their technological investments last as long as
they can.
The introduction of 350-MHz and 400-MHz Pentium II processors, the accompanying 440BX
chipset, and the speedy 100-MHz system bus that it enables may change that situation,
however, at least with regards to processor upgrades. Here's the problem: You can't move
your existing Pentium II processor onto one of the fast new 100-MHz motherboards, nor can
you put one of these speedy new CPUs into your existing PII motherboard. Well, actually,
you can do these things physically, but they won't do you any good.
In the first case, if you put, say, your 266-MHz or even 333-MHz PII into a
440BX-equipped motherboard hoping to eke just a bit more capability out of your expensive
Pentium II cartridge, the system will notice the type of processor you've installed and
automatically kick the system bus speed back down to 66 MHz. That's the same speed as
systems that use those chips currently run at, which means the performance will be
absolutely no different from what it was in your original 266-or 333-MHz system (which, of
course, is still pretty darn good). Similarly, if you try to plug a Celeron, which is
intended for 66 MHz system bus systems only, into a 100-MHz system bus-based motherboard,
the motherboard will kick the system bus back down to 66 MHz.
In the second case, if you were hoping to take advantage of the easy upgradability that
the Pentium II cartridge offers, and bought a 400-MHz version of the chip to upgrade, say,
your existing PII 233, you'd find that the processor itself notices the slower bus speed
and kicks down to run at 266 MHz. (This may not be true for a PII 233 system built with
the 440BX chipset -- which supports both 66-and 100-MHz bus speeds -- but it's definitely
the case for any existing PII systems built around the 440LX or 440FX chipsets.)
It turns out that the fastest a 66-MHz system bus-based PII computer can be upgraded to
is a 333-MHz PII. Now, when the 333-MHz system drops down in price it may be justifiable
to owners of PII 233 systems who want to upgrade, but it doesn't make any sense for 266-or
300-MHz PII system owners (and 333-MHz PII owners obviously have no choice at all).
In recognition of this fact, Intel has said that it is getting out of the processor
upgrade business. It still has a Socket 8 Pentium II OverDrive chip designed to upgrade
existing Pentium Pro systems to Pentium II in the works, but nothing beyond that. The
company has apparently decided that it doesn't make economic sense to offer processor
upgrades for existing computers because there are too many other elements involved to
really improve system performance.
On the one hand, I find this rather ironic; after all, the Pentium II's packaging makes
it suited to offering easy processor upgrades. Yet, I can understand how the technical
issues involved with jumping from one system bus speed to another could prove to be very
problematic.
Regardless of the reasoning, however, what these facts undeniably point to is a
movement away from easy upgradability. Sure, you could upgrade a machine by buying a new
motherboard with the appropriate chipset and a new processor, but the economics of that
particular decision are probably not very good.
Instead, it seems we're moving away from the days of hardware tinkering and bit-by-bit
upgrading, and moving toward the notion of replacing entire machines at once. This idea
first appeared in the sub-$1,000 priced PC arena where, again, it's almost easier to
justify buying a new machine rather than upgrade an existing one. But with Intel's new
Pentium II and chipset introductions, those principles may start applying to higher-end,
cutting edge machines.
As PCs have start to become more like commodity items, perhaps this development of less
upgradeable machines was inevitable, but that doesn't mean it easy to take.
©
Copyright 1998, by InfoWorld Publishing Corp., a
subsidiary of IDG Communications, Inc. Reprinted from InfoWorld,
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