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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 results)
Real World Performance Tests
Intro | Benchmarks  | Apps Tests | Game Tests | Installation | Specs/Design
Applications Performance Tests

This page lists test results in common Mac applications like iTunes, iPhoto, Photoshop 7.0, file compression and time to convert a QT movie to H.264 under OS X 10.4.1 with the Quicksilver G4/733 (640MB RAM, 250GB SATA HD/PCI SATA controller, Radeon 9800 Pro) and the 5 Powerlogix CPU upgrades. It also includes a simple multitasking test. (Time to render a scene with iTunes playing in the background.)
    Notes: (repeated on all test pages)
  • The 1.7GHz 7447A actually runs at appx 1.73GHz in 133MHz bus Macs like the Digital Audio and Quicksilver (QS model used for tests here)
  • For all the Dual 1.7GHz Upgrade tests CPU Director's DFS (Dynamic Frequency Switching) was enabled. It was not enabled for the other upgrade's tests.

I created a separate page on CPU Director 2.1 with screenshots and more info. It worked well (notice the 1.73GHz results vs the 1.8GHz w/DFS disabled) and was responsive (changes speeds quickly).

Multitasking (Render scene w/iTunes playing)
As a simple and easily repeatable multitasking test here's the time in seconds to complete a Cinebench scene render while iTunes was playing in the background. (A simple test but useful for illustrating the benefit of dual CPUs as I suspect many like to listen to iTunes while working.)


You can see the Dual CPU models completed this much faster than single CPU's did.

H.264 HD Playback Performance
As you probably already know (and some have complained about), H.264 takes a lot more CPU for playback than other codecs, but the quality is usually very impressive. Although Apple lists a high end G5 is recommended for HD playback, I decided to compare the playback of the "Fantastic 4" trailer (720p version - 1280x532) at Apple's QT trailers page on the stock system and the 2 CPU upgrades. The difference (as I expected) was dramatic. Performance with the dual 7457 was actually better than I expected. (24 FPS movie, although sometimes playback blipped to 25 FPS)

  • Stock G4/733: 2-11 FPS (but often 4-5 FPS)
  • Dual 1.2GHz 7447A: 12-25 FPS (often 16+ FPS)
  • Dual 1.2GHz 7457: 21-25 FPS (often 23-24 FPS)
  • Dual 1.7GHz 7447A: 12-25 FPS (often 18-24 FPS)
  • Dual 1.8GHz 7447A: 13-25 FPS (often 19-24 FPS)
  • Single 1.8GHz 7447A: 12-24 FPS (often 12-16 FPS)

Quicktime to H.264 Conversion
Time to convert the "Changed Forever" (9/11) QT movie (640x480, 4min: 32 sec. long) to H.264 (320x240) using Quicktime 7.0.1. (H.264 encoding typically takes much longer than encoding of other MPEG types like MPEG2/DVD.)

QT H.264 convert

iTunes MP3 and Lossless Conversion
Time to convert an AIFF Audio track (4 min, 19 second) on the hard drive to both MP3 (256Kbps rate quality setting) and Apple lossless format.

iTunes File convert

This test was timed with a stopwatch, so the margin of error/repeatability of starting/stopping the stopwatch could easily be 1/2 sec. That may explain why the dual 1.7GHz's MP3 conversion time was longer than expected (unless DFS switching was a factor but typically it wasn't in other tests.)

PhotoShop 7.01 Filter Tests
I used the OWC modified version of the PSBench 21 filter (standard/10MB image) action script. The difference in the OWC modified version is that it doesn't repeat each filter test 3 times and doesn't restore the image after every filter. Here's the total time to complete the 21 filter test. (Photoshop was set for 1 History setting and RAM usage prefs set to max.)

PS 7 Filter tests comparison

iPhoto 5.0.2 Image Export to QT Movie Tests
Using iPhoto 5.0.2, I timed how long it took to export/convert my 736 image library (most images were from 5 and 6 MegaPixel cameras) to a Quicktime (1024x768) movie. (The disk may be somewhat of a bottleneck on this and iPhoto doesn't seem to as MP aware as some Pro apps.)

iPhoto QT Export  Results

Archive (ZIP) 1.4GB Folder
Time to Archive a 1.4GB Folder (Halo game folder) to a ZIP file. (1.4GB compressed to appx 483MB.)

Compress file


Apps Tests Bottom Line:
Compared to the stock CPU, all of these upgrades delivered a big boost in performance. (Swapping the G4/733 back in afterwards felt like driving my car with the parking brake fully up...)
You can see in the graphs above the dual 1.8GHz was fastest of the 5 upgrades in these apps tests. The dual 1.73GHz (even w/DFS enabled) was close behind usually and the dual 7457 w/L3 did better than its clock speed alone would indicate. (Makes me wish I had kept it and tried overclocking it to 1.4GHz or so...)
A lot of common/consumer apps aren't that MP aware and if you don't multitask a lot, a single CPU upgrade can be a good value if your budget doesn't allow for a dual.

The next page covers performance tests with several popular 3d Mac games.

Index of PL 7447/7457 CPU Upgrades Review Pages

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

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