Engstrom, Reviews Editor
General Impressions: Two things stuck me as I looked over
the two cards from PowerLogix. They are amazingly small, just
long enough to fit in the processor slot, and they sport a
fan on top of a rather small heat sink. We haven't seen a
fan in use since the untimely demise of the Vimage line of
Software Installation:PowerLogix provides drivers on a floppy
which also serves as an emergency boot disk. More on this
later. Be sure to install the software first as this will
enable the backside cache on restart and install important
system patches. It is always a good idea to make sure you
have the latest version as well. The installer places two
extensions in your system folder. The "G3/G4 Profiler
Init" configures the card with the settings you have
specified and the "AltiVec enabler" makes the system
aware of the AltiVec (Velocity) instruction set on the G4
processor. To see a performance gain you will still need to
be running applications that are written specifically to take
advantage of AltiVec. The last item installed is the "G3/G4
Cache Profiler" which allows you to adjust the speed
of the backside cache and make a variety of other advanced
settings. The cache profiler also lets you disable speculative
addressing. Speculative addressing, also called speculative
processing has been the subject of heated online debate after
Newer Technologies released a "white
paper" warning of data corruption, boot problems
etc. if speculative addressing is not dealt with properly.
This was followed by a rebuttal
from the other accelerator companies, PowerLogix included.
Newer takes a hardware approach to dealing with the speculative
addressing issue, turning off speculation in input/output
space but leaving it on in RAM/ROM space. The other manufacturers
take a software/firmware approach. The issue with the software
fix is that the patch can be erased in the unlikely event
you "zap" your NVRAM. You should note that NVRAM
and PRAM zaps are two
different beasts and zapping your PRAM (a useful troubleshooting
procedure) will not remove the SA patch. PowerLogix provides
an emergency startup floppy which will boot your machine and
restore the NVRAM patch if needed.
| AltiVec Update!
When we originally reviewed the G4/350 and G4/400 we
noted the lack of publicly available AltiVec plug-ins
for Photoshop. As of December 10th, Adobe has made these
plug-ins available on their web site. We noted this
in a recent Product
Watch Page. Before rushing off to Adobe's
download page a couple of caveats are in order.
The plug-ins will only work with Photoshop 5.5 so don't
bother downloading unless you own this version or later.
Adobe also makes no promises when it comes to using
their plug-ins with G4 upgrade cards. Although we haven't
had a chance to test for ourselves, I would assume that
Adobe is just covering themselves legally rather than
anticipating problems. If you own a G4 upgrade card
and are using the plug-ins successfully or not so successfully,
let us know! Post your experiences on our discussion
board or send a note to Don.
Hardware Installation: Due to its compact design, handling
and installing the card was a little unnerving. It was quite
a challenge to avoid touching the card's circuitry as there
is little unused space on the card. Other that this minor
quibble the process was straightforward. The manual includes
instructions for all of the supported machines. The fan's
wiring harness includes a passthrough connector in case you
have maxed out your power supply's feeds. One of my favorite
design features is the strategically oriented 8 dip switches
for adjusting the card's speed. Even once the card is installed,
the switches are visible and easy to get to. I overclocked
the 350 card to 400MHz without having to remove the card.
Just make sure the power is off! In another nice touch, PowerLogix
pastes a chart of possible dip switch settings on the back
of the card for quick reference.
Performance/Stability: The cards operated very well at their
rated speed. Both cards can be overclocked so, at the suggestion
of PowerLogix, I set both cards to 50MHz over their "native"
speed. The G4/350 jumped up to 400MHz (backside cache at 200MHz)
without skipping a beat and closely matched the performance
of the G4/400 across the board. Pushing the 400MHz card to
450MHz was more problematic. I experienced repeated crashes
during the boot process and stalls when trying to load the
finder. Booting with extensions disabled allowed a successful
boot but on these occasions only one of the 9500's two hard
drives would mount. Setting the backside cache to a 5:2 ratio
(180MHz) fortunately eliminated all of these issues but also
caused a performance hit over the more desirable 2:1 (225MHz)
ratio. See scores below
for a comparison of native vs overclocked speeds. Some cards
may have more "headroom" than others so your mileage
Test Machine Configuration
Our test machine was a 9500 with 96MB RAM and OS 9 installed.
We tested with an extension set comprised of all OS extensions
plus those installed by PowerLogix. For the MacBench tests
virtual memory was turned off and disk cache was set to 512k.
These settings are consistent with those used on the MacBench
base reference machine, a beige G3/300. For the real world
tests we turned virtual memory on and set it to 97MB.
||Excellent performance &
stability even when overclocked to 400MHz, easy access
to dip switches, 3 year warranty
||Excellent performance &
stability at native speed, can be overclocked to 450MHz,
easy access to dip switches, 3 year warranty.
||Small size makes it awkward
||Can't maintain 2:1 cache ratio
at 450MHz without instability, small size makes it awkward
MacBench 5.0 Scores
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 mean better performance.
For more detailed information on MacBench click
here. Remember, MacBench 5.0 came out well before the
G4 processor and was consequently not written to take advantage
of or test the AltiVec (AKA Velocity) instruction set.
"Real World" Tests
(Shorter bars are better)
Time to Scroll a 574 page AppleWorks document
from top to bottom.
Using the same document as above we did a
search/replace command to replace the word "the"
with the word "macbench," over 12,900 occurrences
Photoshop 4 "Real World" Test
All scores are relative to the stock 9500
which was assigned a score of 100. Lower numbers and shorter
bars are better. Bear in mind that with the exception of
the last test, we didn't use a "Velocity/AltiVec"
plugin as neither PowerLogix nor Adobe provides one. You
should also be aware that the plugin (including the one
that ships with new G4 systems) doesn't provide a performance
boost across the board, just on specific filters and operations.
Just to give you an idea of the AltiVec advantage,
we ran a test using the Photoshop plugin that XLR8 provides
with their cards. We ran the same filter operation twice
for each card, once with the plugin and once without. The
filter operation without the plugin was assigned a score
of 100. As you can see, the plugin makes a bit of a difference!
Render Boy 2.2.0
Time to render "Pool Table" Example
SoundJam MP3 Encode
Time to encode a CD track 4 minutes 26 seconds
in length. Scores for the 350MHz card overclocked to 400MHz
were not included as they were virtually identical to the
"native" 400MHz card.
Variable/Fixed Clock Rate
||Heat Sink/Fan combination
Toll Free Phone
||Heat Sink/Fan combination
||Toll Free Phone