recently defunct Newer was the first to come out with an upgrade
for the iMac, the G3 iMAXpowr which ran at 466MHz. They followed
up this unique upgrade with a G4 upgrade for the iMac (A-D).
Alas some months later Newer shut its doors and these upgrades
are no more.
Luckily PowerLogix stepped into the breach with their own
iMac upgrade, the iForce G3/466, and it has some distinct
advantages over the previous Newer offerings.
Though Newer was hailed for coming out with an upgrade for
the iMac their upgrades were expensive and you had to send
in your old processor in a short time frame, if you wanted
a rebate off the price of the upgrade. Basically what Newer
was doing was refitting old slow iMac processor cards (the
ones customers sent in when they bought an iMAXpowr), with
faster processors, and then reselling them. This was how they
legally provided the special proprietary instructions that
reside in the ROM chip which Apple placed on the iMac's processor
card - basically by retrofitting stock cards.
It was a cumbersome process and, if you sent in your old
card for the rebate, you would not have it to reinstall should
something go wrong with the new upgrade.
Apple: iMacs A (233MHz), B (233MHz), C (266MHz) and
Mac OS 8.1 to OS 9.1 supported
Well PowerLogix came up with a devilishly simple solution!
Why not, since you already own the ROM information on your
current iMac's processor card, transfer it to the iForce upgrade
card. And that is just what they made possible. The software
that comes with the iForce card, copies your current ROM instructions
to your hard drive. You then install the upgrade card and
the software copies the instructions into the ROM chip on
the new iForce card. Very clever, and you get to keep your
We found the iForce card to be extremely stable during its
three week stay in our G3/233 iMac. Its performance was close
to double the stock iMac in processor intensive tasks. For
the moment the iForce is the only game in town for iMac owner's
wanting to upgrade their machine's processors.
Great Prices On Upgrades Check The Vendors Below
Installation: The CD that comes with iForce upgrade contains
a 'chaplinesque' silent QuickTime movie that gives you a visual
overview of how to perform the installation. It is worthwhile
watching the movie, if you have never taken apart your iMac
before. If you have installed additional RAM into your machine,
you will have no problems installing the iForce upgrade, which
involves a similar procedure. If you haven't gotten into the
guts of your iMac previously, taking apart your iMac may seem
daunting. It really isn't that bad but if you're not mechanically
inclined let a professional install the iForce for you.
The iForce comes with PowerLogix's traditionally minimalist
installation manual. Though it won't win any publishing prizes,
it does cover all the pertinent information you need to know
in a clear concise manner. As mentioned above, you will need
to run a software utility that will copy your original ROM
instructions to the hard drive and then back to the iForce
upgrade once you have it installed. It is important when first
starting up the iMac, once the upgrade is installed, that
you do not interrupt the process of the ROM instructions being
copied to the iForce card.This process occurs automatically
and if interrupted will make the iForce card inoperable.
Other than that, installing the upgrade is fairly straight-forward.
You need to remove the logic board from the iMac, remove the
old processor card, transfer the RAM from the old card onto
the iForce card, install the iForce card onto the logic board,
put the logic board back into the iMac and boot your new raging
beast up. The iForce requires no enabling software - in other
words no extension or control panel - to operate. It does
come with a software utility that will tell you the speed
of the processor and its backside cache. The utility will
also show the operating temperature of the upgrade. Interestingly
the iForce ran much cooler that the original processor - 31C
as opposed to 55C for the stock processor.
A couple of points to make before leaving the installation
section. PowerLogix, in their installation instructions, have
you boot the upgraded iMac, with all its cables and cords
connected, while the machine is still apart (the logic board
still out of the machine). Not only did we find this very
difficult to do but we also think that this is not wise from
a safety standpoint. We strongly recommend that you do not
follow this part of their instructions. Put everything back
in its place and then boot the machine for the first time.
The only advantage we can see to the PowerLogix method is
that, if something goes wrong you don't have to take the whole
machine apart again. Spend the extra few minutes and put it
Also PowerLogix recommends that you use a screwdriver to
pry your old processor card from the logic board. We suggest
using the heatsink clip, which is ideally suited for performing
this task. As always, take the precaution of removing any
static electricity that may be built up in your body before
handling the logic board or its components.
Performance and Stability: The stability of the iForce upgrade
was excellent. We had zero problems with it!
In the performance arena, the card showed an almost doubling
of speed in processor intensive tasks over our stock iMac
G3/233. Graphics performance was also improved, showing a
45% improvement in scrolling speed and 25% in Quake III FPS
in fastest mode. Of course if you have the 333MHz version
of the iMac your performance boost will be less dramatic ....
more like 50% performance improvement in processor intensive
Conclusions: PowerLogix no longer manufactures the 466MHz
version of the iForce. Instead they have 400MHz and 500MHz
versions. You can assume for the 500MHz cards that the scores
below will be 7 - 10% faster, and for the 400MHz card 15 -
20% slower, on processor intensive tasks. The iForce upgrade
performed extremely well and we can wholeheartedly recommend
it on this point. If you rely on heavy-duty processing power
to get you through the day, the iForce will certainly help
you out - in a big way. However the top of the line 500MHz
card is expensive at $500. You may be better off selling your
aging iMac and buying a new machine. A new 450MHz iMac with
all the new technology should run you a little over $1,000
which would be just about be the cost of the iForce card plus
what you could get for your old iMac. The 500MHz card will
become a more attractive buy as its price drops ... which
it inevitably will.
For owners of 233MHz iMacs the 400MHz iForce card may be
a better deal. For $300 you will see an improvement of between
60 to 70% in processing power.
PowerLogix says that they have a G4 upgrade under development
for the iMac which may be announced at Macworld Tokyo.
Hits: Very Good performance, very stable, good technological
Misses: Manual could be beefed up, installation advice
more cumbersome than it needs to be, successor card
SRP: This card is no longer sold. Technologically similar
iForce cards running at 500MHz and 400MHz cost $500
and $300 respectively
MacBench 5.0 Results
The scores below are from MacBench 5.0. MacBench 5.0 is
a subsystem-level benchmark that measures the performance
of a Mac's processor, disk, and graphics subsystems to name
a few. MacBench normalizes all scores relative to the base
machine, a Power Macintosh G3/300. The base machine receives
a score of 1000. For all MacBench tests, higher numbers indicate
"Real World" Tests
The tests below are from our newly revised
suite of real world application tests. These tests feature
a diverse selection of applications commonly used by the Mac
community. The test suite was designed to render an accurate
and well rounded picture of an upgrade's performance. Click
here for detailed information on each test and our machine's
configuration. All of the tests below (with the exception
of the Quake III tests) were timed with a stopwatch. The times
are then converted to percentages with the unaccelerated machine
set to 100%. Higher0 numbers indicate a better score.
Copyright 1996-2003 by Cider Press Publishing LLC all rights reserved.
MacSpeedZone is not authorized, sponsored, or otherwise approved by Apple
Computer. Apple, the Apple logo, Macintosh, iPod, iBook, iMac, eMac, and
PowerBook are registered trademarks of Apple Computer, Inc. Additional
and product names may be trademarks or registered trademarks and are hereby