Evan Kleiman
- 2002.12.04
If you've read any of the Mac performance and benchmarking
sites, such as Bare
Feats and Accelerate Your Mac,
you've probably seen an example where a 500 MHz G4 system with some
upgrades outperforms a stock 600 MHz G4 computer.
Why does this occur? The 600 MHz processor in our hypothetical
example runs much faster than the 500 MHz one, so it should win.
All that matters is megahertz, right?
Well, no.
"Megahertz-myth" is a buzzword that has been thrown around for a
while. Many people buy a computer because it has a 1.2 GHz
processor (or something of the like). These uninformed consumers
are the reason most computer companies sell their computers so
cheaply.
Conversely, people who do know are the reason Apple sells their
computers for so much compared with other personal computer
makers.
The bottom line is that in today's ultra-fast computing
world, megahertz means almost nothing. But what does mean
something when buying a computer and comparing it to others?
Bits and Pieces
Like cars, houses, and many other things, computers are made up
of several different subsystems or devices. The components in your
computer operate together, often running no faster then the slowest
part. This brings us to our next buzzword: bottlenecks. A
bottleneck occurs many ways in a computer. But, either way, it's
all the same. You could have the fastest dual G4 Apple makes, the
newest software, and a great hard drive, but if you can't get the
information on the screen fast enough because you have a slow video
card, then much of that power is wasted.
This is part of the reason Dell and Gateway can sell their
computers so cheaply. 1 GHz and faster Pentium and Celeron
processors can be had rather cheap, and that makes the core of a
cheap computer when a cheap video card helps offset the cost of a
"high speed" CPU.
Most buyers don't know about bottlenecks. They'll see a computer
with a fast processor and assume that it's fast. I've often seen
these bargain-basement brands, such as eMachines, sel a "fast"
computer with an excruciatingly slow hard drive or other component.
They can sell these computers so cheap because, while the processor
might cost them a little bit more than average to produce or buy,
the cheap components lower the overall price of the system.
However, to the buyer it still looks like a great, fast
deal.
The last selling point that computer manufacturers use to market
their "unbalanced" products is memory. A lot of companies will sell
their computers with huge chunks of memory. However, the fact of
the matter is that unless you're doing some sort of high-end gaming
or desktop publishing, anything over 256 MB is probably more than
you need. Of course, with vendors promising great performance from
some computer with 512 MB or more for a cheap price, the offers
seem unbeatable - but don't be fooled. Memory is one of the
cheapest components in a computer, so companies can sell computers
with far more than you'll ever need. It makes the computer more
appealing to everyone except the true computer expert.
- Editor's note: Too little memory can create bottlenecks,
forcing the computer to use the hard drive as virtual memory and
slowing overall performance. There is no penalty for having too
much memory beyond the cost of the memory, but there can be a
significant performance penalty for having too little. The more
programs you run at once and the newer your operating system, the
more RAM you need. dk
Memory confusion is also found in video cards. There are very
many high-end video cards that are placed into a computer. Often
times, companies will sell this as a "gaming platform," yet it will
have a slow hard drive and barely enough memory to play Doom I.
While these ultra-fast 128 MB video cards are great for gaming,
most low-end Mac users don't play the newest high-end games, so
they don't really need this kind of card. Even when running
OS X 10.2's Quartz Extreme, 128 is more than you'll ever
utilize.
This brings up another topic: misnaming. Misnomers are
commonplace in today's computing world. For instance, I have a Rage
128 video card in my Blue and White
G3. This 128 can mean many things, such as video memory, bus
speed, etc. But, this 128 seems to have no bearing on any of these
aspects.
This is also true with the AMD Athlon 2100+ processor. Its clock
speed is not 2100 MHz. It's called this because the 1.73 GHz CPU is
"as fast as" a 2.1 GHz processor. Sounds like another way to fool
buyers to me.
- Editor's note: On the flip side, the Intel Pentium 4 is roughly
25% less efficient than the older Pentium III at the same clock
speed, but because of the ease of marketing MHz instead of overall
performance, Intel is making out like a bandit selling 2-3 GHz
CPUs. dk
If these companies are emphasizing the wrong things when
marketing their computers, what should we buy? We can only hope for
more honesty and better balancing of premade computers from these
vendors in the future.
Until then, you had better rely on computer websites that
thoroughly test the whole computer. One component doesn't make a
huge difference. All the components in a computer work as a
team.
The truly fast computer has a balance of components, and while
they're not necessarily the fastest individual components, they can
work faster than a computer designed around a single very fast
component.
