Hit the afterburners. Let's tear this highway apart.
The information superhighway that is.
Okay, cheesy metaphors aside, hitting the afterburners on your old
Mac might not be as hard as you think. There's plenty you can do with a
little research and some minor work.
Start by researching your machine. Google the machine name in
quotations. You'll probably find all of the complaints, moans, and
gripes about it. My first step is to patch up specific machine flaws
and weaknesses if possible.
For example, on my Rev.
1 Blue And White G3 I needed to purchase a PCI ATA card in order to
circumvent the 128 GB limit on internal ATA drives and to allow
multiple drives on the same channel. The onboard ATA controller on
these machines has a known fault that causes data corruption when more
than one drive is on the same channel.
Or how about the "Lombard"
PowerBook G3 that will only detect 256 MB PC66 SO-DIMM sticks. On
speeds higher than PC66 (PC100, PC133), the computer will only detect
half of the memory or nothing at all. There is also another interesting
issue with this machine. During a Mac OS X 10.3 "Panther" install,
having a memory stick in the top slot will cause the install to fail
with a screen image "melting" effect.
It's important to be aware of these limitations and caveats when
upgrading. It can save you a lot of time, money, and headaches.
Storage and RAM
The most commonly upgraded portions of the system are the hard drive
and RAM. This is mostly due to how easy (though not always!) it is to
do. Upgrading both of these in your machine is a great way to
familiarize yourself with your system and it's internals.
When upgrading the hard drive, there are some important things to
keep in mind. First of all, you have to find out what bus your hard
drive resides on. There are some apps (and sites) that you can use.
I'll discuss that a bit later on. You should also pay attention to what
speed your hard drive spins at and if your computer's hard drive bus is
limited to 128 GB and below drives. A hard drive that spins faster than
your original one can do nothing but benefit you. A hard drive that
spins slower will have lower performance but will still work.
There have been reports of people converting their machines
(specifically notebooks) using CompactFlash-to-2.5" IDE converters.
While I'm not against the prospect of cheap solid state drive (SSD),
there is a certain line that cannot be crossed. I made the mistake of
choosing a CompactFlash (CF) card that was way too slow for any real
world use. I highly recommend 300x and above CF cards - and make sure they have UDMA support.
For RAM, it's roughly the same guidelines. Pay attention to the type
of RAM and RAM slots you have. There are some Macs that will operate
with faster RAM - and some that will not. My best advice is to avoid
taking a risk by getting the exact RAM speed originally used by your
system. Another thing to watch for is hitting your RAM ceiling per slot
and the overall RAM maximum.
For this, I'll use two examples. First, the first generation MacBook.
This machine is limited to 2 GB RAM period. Any more than that
will cause a kernel panic on startup (or the other remainder of the RAM
will not be paged). However, the Santa Rosa-based MacBooks
will support 3 GB of RAM (despite Apple's specs stating it only
supports 2 GB). It's best to do your research for best
results.
The second example is the Blue & White G3. Currently, my B&W
has 1.5 GB of RAM installed. However, the per-slot maximum is only 256
MB, so on 256 MB of the two 512 MB sticks I have installed are used.
The system reads 1 GB of RAM in OS X.
OS X is a known RAM hog. If you're planning to run OS X, do
your best to double the minimum requirement for the build of OS X
you plan to use. You'll notice a high performance boost.
Processors
Processors have scared many away. They can be intimidating at first.
But if you take things slowly and do plenty of research, you'll be just
fine.
A good place to start if your looking to upgrade an older desktop
(G4 older) is upgrade vendors, including Sonnet and Daystar Technology. Play around in
the processor upgrades section. Learn the sockets and which upgrades
are compatible with which Macs. These companies pioneered many
upgrades, many of which are currently running in machines that I own. I
can vouch for their quality and performance. Don't forget about
NewerTech and
PowerLogix, although I don't
have hands on experience with their upgrades.
Generation gaps are a large hindrance. However, the architecture
that Apple used in the PCI Power Macs (604e and earlier) can be
upgraded all the way to G4 chips. I'll let you find the rest out for
yourself. It's the same for the G3 Power Macs, upgradable to G4. And
the older G4s can be brought all the way up to 1.0 GHz and way
beyond.
Aside from aftermarket upgrades, there's another way to upgrade your
processor: Find a faster one from the same model. Be careful. From the
Digital Audio up to
the 2002
Quicksilver, the Power Mac G4 used the same 133 MHz system bus.
However, after that the system bus was bumped to 167 MHz to support
higher clock speed processors. This means that you may not be able to
use a processor from the same model (but with a higher clock speed) to
upgrade your machine. You may need to find a new motherboard in that
case.
This especially applies to the G5s. They are impossible to upgrade
without doing a motherboard swap.
Things to specifically pay attention to when it comes to dealing
with processors, are system bus speed and socket. When it comes to
aftermarket upgrades, most manufacturers will list compatibility with
certain models.
If you're planning on upgrading your notebook's processor, I've got
some bad news for you. If your laptop was manufactured after the famous
"Pismo" PowerBook G3,
you're out of luck. The processors in G4 PowerBooks and iBooks are BGA
(Ball-Grid Array), and they are soldered directly to the motherboard.
(There used to be a service in which Daystar Technology offered to
upgrade these chips, but it no loner offers that service.)
Intel Macs
There is a common misconception that processors cannot be upgraded
in Intel Macs. This is wrong. The iMac Core Duo, Mac mini Core Solo/Duo, and iMac Core 2 Duo all use the
same standard ZIF socket (Socket M). Although you would be treading on
a road less traveled, as long as you follow the socket and bus speed
rule, you're in the golden zone.
Sights and Sounds
Upgrading video cards in Macs products has often been tricky. It's
sometimes a juggle between getting a card for which there are no
up-to-date drivers or getting a card that has a PC BIOS. Either way,
the card is useless to you.
Aside from those possibilities, there are also different buses.
There are various cards made for each bus type, dating all the way back
to NuBus. These
include PCI, AGP (in different speeds), PCI-X, and PCIe. Chose wisely,
and do your best to ensure compatibility with your Mac before you buy.
I recommend Strangedogs for
great information on flashing a PC BIOS-based video card to a
Mac-compatible card.
For the average user, the built-in sound is usually sufficient. I've
used various Macs as jukeboxes, and they sound great for what they are.
Again, it always helps to have the spec sheet of your computer
available so you know exactly what you're getting into. Adding powered
speakers or connecting to your stereo
system can provide a lot more volume.
Conclusions
My absolute favorite app for offline viewing of machine
specifications is definitely MacTracker. It's got quite an
extensive database, and (relatively) low system requirements. For
online, of course, I use Low End Mac. :)
Another favorite tool of mine is iFixit. They've got a multitude of guides
and FAQs on many machines, including step by step picture guides to
opening up your machine. If you're afraid to crack it open because
you've never done it before, relax . . . they've done it for
you.
Your strongest tool when it comes to upgrading is the ongoing
experiences of others. Learn from other people's lessons and avoid
making the same mistakes.
Your second strongest tool is your intuition.
Above all, do your research. 
