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Accelerate Your Mac! - the source for performance news and reviews
The Source for Mac Performance News and Reviews
Review: Powerlogix's 7447A & 7457 CPU Upgrades
(Single and Dual CPU - 1.2GHz to 1.8GHz)

Tests in Quicksilver G4/733
By Mike
Published: 7/1/2005
Updated: 8/9/2005 (for 1.7/1.8GHz models)
Installation Notes, Photos and Observations
Intro | Benchmarks  | Apps Tests | Game Tests | Installation | Specs/Design

The PowerForce G4 Upgrades included:

  • CPU module w/attached heatsink
  • CPU Fan w/2 screws (attaches to heatsink)
  • The Dual 1.7/1.8GHz CPU models also included a small Fan for use with Digital Audio/Quicksilver models.
  • CD (bootable) with firmware patcher, Install guides (PDF and QT Movie)

Note: The install guide PDF used a Sawtooth tower (no OEM CPU fan); the Quicktime movie used a Quicksilver/Digital Audio model with the OEM CPU fan at the rear of the case. The OEM fan is removed, it's retained by 2 screws in the back of the case. Actually there appeared to be enough clearance to reuse the QS 733's fan, but I didn't use it. However as mentioned below, the Dual 1.7/1.8GHz upgrades included a small fan for that area and a instruction sheet to install it if you had a Digital Audio or Quicksilver Mac model for improved cooling.

Firmware Patching: Since these CPU upgrades are based on the 7447A and 7457, you must patch the system firmware before installing the CPU module. The included Powerlogix CD is bootable and has a patcher included. The install guide covers this procedure, but basically it's similar to applying an apple firmware update. You hold in the programmers button/switch on the front of the case while pressing the power button. Hold both until you hear the high pitched tone, then release them and hold the C key to boot from the PL CD. The PL CD boots into open firmware and automatically runs a script that shows a menu of options. Pressing the "4" option applies all the patches (system firmware, OS 9.x NVRAM patch, etc.). If the firmware has already been patched the script checks for that and displays a menu to remove any or all of the patches.

Hardware Installation: A basic outline of the steps involved:

  1. Shut down Mac, discharge your static electricity (touch metal part of case), then unplug the AC power cord.

  2. For Digital Audio/Quicksilver models (only) with a CPU Fan:
    (Update - the latest dual PL upgrades include a small fan for mounting in the rear of the DA/QS model chassis. I'll have updated photos of this posted soon.)
    • Remove the 2 screws from the back of the case that secure the original CPU fan's plastic housing.

    • If there's a plastic cover over the original heatsink, lift the plastic tabs on the heatsink cover/fan assembly to allow removing it from the heatsink. (Dual G4/533 and Single G4/733 Digital Audio model had this heatsink cover/fan assembly - not the G4/466 model, nor the Quicksilvers.) The QS 733 model CPU fan plugs into the logic board (lift it off), the Digital Audio model fan connector is on the module.

  3. Remove the 2 heatsink retaining clips, then the original heatsink.

  4. Remove the 3 or 4 (depending on model) philips screws retaining the original CPU module and lift it off the motherboard connector.

  5. Remove the protective cover from the Powerlogix module's connector on the bottom of the board.

  6. Visually align the Powerlogix CPU module over the 3 mounting screw holes and press down to seat the connector.

  7. The PL upgrades shipped with the fan attached to the heatsink - remove the 2 screws securing it to the heatsink and install 3 screws to secure the upgrade module to the motherboard.

  8. Attach the Fan to the heatsink using the 2 screws provided (fan label side dow - Fan must be blowing DOWN on the heatsink for cooling)

  9. Connect the wiring to a spare hard drive power connector. (Wiring included has a "Y" adapter to provide another connector for use.)

The start to finish hardware installation took about 5-10 minutes tops (not rushing). Here's photos of the original QS 733 and of the installed CPU upgrades:

Stock Quicksilver G4/733
stock QS G4/733

PowerForce G4 Dual 7457 Upgrade Installed
7457 Installed

PowerForce G4 Dual 1.8GHz 7447A Upgrade Installed
(using new heatsink and small aux. fan)
7447A Installed

The photo above shows the new heatsink on the Dual CPU models for improved cooling. Robert Jagitsch of Powerlogix commented on the revised heatsink design:

" The revised heatsink has some additional cooling vents, and the fan is moved over to the other side of the heatsink. This makes for much better flow over the power supply, and better flow in general due to the more room over the fan when the case is shut.
-Robert Jagitsch
Powerlogix "

The revised heatsink also had an improved CPU/HS contact area compared to an earlier design (that was never shipped I was told). With the new heatsink on a Dual 1.8GHz upgrade I saw a max reported temperature (from the on-board sensor) of appx 66°C during a 24-hour/100% CPU load stress test.

Note: Inside the box of the Dual 1.7GHz and Dual 1.8GHz upgrades was an aux. small fan to be used for Digital Audio and Quicksilver models and an instruction sheet on installing them in the same location on the back side of the case where some DA/QS models had an original Apple fan. (See the above photo for a picture of the small fan behind the upgrade.)
These dual CPU upgrades also had an improved heatsink design which reduced temperatures reported by CPU Director 2.1 (from on-card sensor) by more than 15°C in 24-hour/100% CPU load stress tests.

Tests of Deep Sleep/Wake from Sleep:
In the first post of this review I mentioned that due to a very early model Firmtek SerialATA PCI card (used to drive the 250GB boot drive), Deep Sleep was not possible even with the stock CPU. Firmtek saw that comment and sent one of the current models to replace it. I'm happy to report that deep sleep and wake from sleep worked fine with all the CPUs tested in this review. (I have energy saver set to never allow drive sleep on all my towers, so I use the Sleep Menu item to put the system to sleep.) Remember however some PCI cards/connected devices can prevent deep sleep (see reports on the systems and Firewire topics pages here).

Noise and Temperature Observations:
The upgrade's fan wasn't really noticeably louder than the original Quicksilver CPU fan IMHO. (See the specs page for fan details - they're spec'd at 31dBA and 34dBA) and were quieter than a rev B MDD system. None of the fans had the high pitched noise/whine of high rpm fan. (Of course noise is a subjective thing - some will complain about any fan period.)

As noted in Motorola's own spec docs, the G4 does not provide accurate CPU temperatures (using software utilities) and later versions don't support that feature (present in 7400/7410 series G4). Powerlogix's CPU Director 2.1 when used with these Powerlogix CPU upgrades will report the temperature from a sensor on the Powerlogix upgrade. (This is not the internal CPU junction temperature, it's the temperature of the upgrade board and onboard power supply/vreg. Currently other brands of upgrades do not have this temperature sensor on them.)
During 24-hour stress tests (with both CPUs literally constantly pegged at 100% usage) of the dual 1.8GHz, the max reported temperatures were appx 66°C.

System Compatibility:
These 133MHz bus PowerForce upgrades are compatible with the following Mac models:

  • Apple G4/AGP "Digital Audio"
  • Apple G4/AGP "Quicksilver"

Powerlogix also has models for the 100MHz bus "Sawtooth" and "Gigabit Ethernet" Towers as well as the G4 Cube. (DFS would be a big plus for the Cube IMHO.) See OWC's Powerlogix upgrades page which covers all of them. (Note: For "Sawtooth" (first model G4/AGP tower) owners, dual CPU upgrade support requires a Uni-N (chipset) revision 7 or later. The first Sawtooth tower I bought in fall 1999 had a Uni-N rev 3, the next shipping sawtooth Uni-N version I saw was 7 in early 2000.)

OS Requirements: (from the OWC product page)

  • These upgrades require MacOS 9.2.2*, MacOS X 10.2.8 or 10.3 Panther. (Tiger is also supported - I ran all tests here using OS X 10.4.1) Classic in OS X 10.2.8 and 10.3 is fully compatible. PowerLogix also includes a firmware update so the system properly recognizes the 7457 processor. This update is required (but is easily reversible.)
  • Note: The dual card operates in single CPU mode under MacOS 9.2.2. For full dual functionality OS X is required.

And as with any 7457 (and I believe 7447A) upgrade, if you're booting to OS 9.x you have to remove the Apple CPU Plugins extension. (For any OS 9 bootable CD you want to use, you'll also need to make a copy of it without the extension.)

The next page has information on the Powerlogix Upgrades CPU, cache and fan. Or you may use the links below to jump to a specific page.

Index of PL 7447A/7457 CPU Upgrades Review Pages

Intro | Benchmarks  | Apps Tests | Game Tests | Installation | Specs/Design

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