There has been lots of talk of how the Mac mini should depress prices
for used G4 Macs (for example: Low End Mac's Best Used Power Mac G4 Deals
and My Mac's After the Mac mini,
is there still a market for used Macs?). Prices have fallen
somewhat, but the value equation has not yet dropped to the point at
which I would find a used G4 tower a competitive deal compared to a new
Mac mini.
My university is offering surplus dual processor 533 MHz/40 GB/512
MB G4 machines for $499 with no monitor, no mouse, and no keyboard.
I was tempted at first, but then did a comparison and changed my
mind.
|
Mac mini
|
Dual G4/533
|
|
G4 CPU speed
|
1.25 GHz
|
equal to 850 MHz
|
|
Bus speed
|
167 MHz
|
133 MHz
|
|
Memory
|
256 MB
|
512 MB
|
|
Display card
|
ATI Radeon 9200
|
Nvidia GeForce 2 MX
|
|
Video memory
|
32 MB
|
32 MB
|
|
Operating system
|
OS X 10.4
|
OS X 10.2
|
|
Software
|
iLife '05
|
none
|
|
Warranty
|
one year
|
none
|
Those are all relative concepts, so to put a price tag on the
difference, a price differential was calculated by comparing the specs
and then subtracting the same percentage of the price as there was
percentage difference between the specs from the starting price of the
Mac mini, because the used G4 was, for the sake of argument, worth that
much less than the new Mac mini. The data are displayed in the table
below, following the explanation of how the figures were arrived
at.
The cost of adding additional memory to the Mac mini (BTO from
Apple) was added to the price of the Mac mini make it equal the memory
capacity of the G4. This started the price of the Mac mini at $550.
This Week's Best Used Power Mac G4 Deals says that "[a]s a very
rough guide, a dual CPU model will outperform a single CPU model with a
60% higher MHz rating under OS X," which means that the dual
processor G4/533 is roughly equivalent to an 850 MHz single-processor
computer. That makes the Power Mac [850 MHz equivalent] approximately
32% slower than the Mac mini. That means that the G4 should be roughly
one-third slower (and less productive) than the Mac mini.
The Power Mac's bus is 20% slower than the mini bus. That means that
the G4 should be roughly 20% slower than the Mac mini. Since it is a
dual CPU G4, however, for the sake of argument, the price differential
will be considered to be only 10%.
The video cards (with 32 MB each) are considered equal for the sake
of this comparison.
The cost of Tiger and iLife '05 (from OWC
and Small
Dog) were subtracted from the price of the G4, because the Mac
mini comes with them installed, while I would have to buy them for the
G4.
To approximate the value of the one-year warranty, the cost of 2
additional years of Apple care ($149) was divided by two, and the
result was subtracted from the price of the G4.
No value was added or subtracted for the keyboard, mouse and
display, as I have those already.
Price Differential
Starting Price for the Mac mini: $550
CPU speed: -$176.00
- Bus speed: -$55.00
- Display card: 0
- Tiger: -$99
- iLife: -$79
- Guarantee: -$74.50
- Total value: $66.50
The surprise total seemed to indicate that I should pay $66.50 to
take the used dual processor G4/533 away, which is taking the argument
to its illogical conclusion.
Editor's note: We realize that this article takes things to an
illogical extreme. While CPU performance can be compared relatively
easily, bus speed has far less impact on performance. Further, this
article does not take into consideration the Power Mac's expansion
slots, use of a 3.5" hard drive, multiple internal drive bays, and
ability to use newer AGP video cards - none of which may matter to the
potential Mac mini buyer.
A used Power Mac G4 does have some value. In deference to the
"megahertz myth," the value equation was recalculated using just the
value of Tiger, iLife and the "new vs. old" premium (i.e. the warranty)
from the price of the used dual processor G4/533.
All other things being equal under this valuation scheme - which
they are not - the used Power Mac is only worth $319. At that
price, I might begin to be interested in one for a low-intensity
workstation, which is the use for which the winner of this price
comparison is destined.
Prices will not start to fall to this level, however, until those of
us in the used Mac market begin to conceptualize this price
differential and vote with our Mac-buying dollars that prices for used
Macs are too high in comparison to the Mac mini.
It has reshaped the whole Mac marketplace, and its effects are just
beginning to be felt. 
Share your perspective on the Mac by emailing with "My Turn" as your subject.
