The SpeedZone: iMac G4/800 vs iMac G4/1GHz .. How Much Faster Is The GHz Machine?

In drive performance both the GHz and 800 MHz iMacs reach the finish line about the same time. The GHz machine tested slightly faster but only ever so slightly. In basic processing power the GHz iMac pulled ahead of the 800 MHz one by 20% .. just what you would expect.

In Game performance, because of its faster graphics card with twice the video memory, the GHz machine bested the 800 MHz by up to 40 percent.

Bear in mind that you are paying $500 more for the extra speed and features of the GHz iMac.

Difference and similarities of each machine

"Real World" Tests

For the graphs below frame rates were converted to percentages, relative to the Power Mac Dual G4/1000, which is set to 100%. For all scores, higher numbers are better.

The copy folder test not only stresses drive performance but also takes advantage of faster processing capability & caching schemes.

In the single file test the the processor & caching capability of the machine is less of a factor. As you can see, the iMac have pretty powerful drive performance

In this test only 55% of the processing power of the Dual GHz Tower was being used, while 100% of the two iMac's processors were saturated with data. This is good news if you want to do other chores with your Tower while you import that 50 GB movie. It is bad new if you don't. There is some bottleneck in the process that keeps the dual processor machine from performing up to its potential .. wasting valuable processing capacity. Perhaps the drive is not feeding data quickly enough to the processor or there is some limiting factor in the software itself.

Let 1K Windows Bloom is a simple carbon application that opens and closes 1,000 windows. This gauges how fast screen redraws are taking place.

Large Document & Database Type Tests

Microsoft Office X Word Macro

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	61%	76%

A Macro (series of complex actions) was run in Microsoft's Excel spreadsheet program. Excel is part of Office X

Microsoft Office X Excel Macro

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	64%	72%

A Macro (series of complex actions) was run in Microsoft's Excel spreadsheet program. Excel is part of Office X

AppleWorks Search And Replace Test

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	59%	81%

This test takes place in a large AppleWorks document. Machines with larger chip caches do better in this test

Finder File Search

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	64%	69%

Mac OS X's new File Search function relies on both processor and drive performance

Number Crunching & Rendering Tests

Photoshop 7 - BareFeat's Test

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	57%	65%

BareFeats Photoshop Test Suite - mimics a production type workflow in Photoshop.

Photoshop 7 - AltiVec Tests

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	44%	55%

Certain of the functions of Photoshop can take special performance advantage of the G4 processor. A dual processor machine runs rings around a single processor one, in this test.

Photoshop 7 - Normal Tests

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	68%	86%

The test above consists of Photoshop functions that do not take any particular advantage of the G4

iMovie - Effect Render

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	51%	65%

An Effect Render is run on an Movie using iMovie. This tests takes advantage of dual processors. 20% of the Tower's processing capability was left idle

AltiVec Fractal (Carbon)

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	40%	50%

The Fractal program has been highly tuned to take advantage of the G4 and is precisely the type of work that the G4 was made for. It will also gobble up whatever processing capability is present. This is a good test for assessing the fundamental processing potential of each machine. Really highlights the processing advantage of a dual processor machine

Encoding/Decoding Tests

QuickTime Encode

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	56%	69%

A QuickTime encode compresses a QuickTime movie for streaming on the Web.

QuickTime Convert To DV Stream

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	63%	75%

Converting QuickTime movies to DV allows you to import them into iMovie.

iTunes - MP3 Encode From CD

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	65%	84%

During the encode 65% of the processing capacity of the dual processor machine was used. On the iMacs 100% was used. The two iMacs read CDs at up to 32X, the Dual Processor Tower at 24X

StuffIt Expand

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	72%	88%

Multitasking

iTunes MP3 Encode + AppleWorks Search & Replace + Finder Copy (Multitasking)

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	43%	55%

MP3 Encode, AppleWorks search & replace and folder copy are all carried out at the same time. In a production type environment the Dual Processor Towers make a lot of sense ... if you do some planning.

QuickTime Encode + Fractal (Multitasking)

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	36%	47%

QuickTime Encode encode and Fractal render are both carried out at the same time.

QuickTime DV + iMovie Effect Render (Multitasking)

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	44%	54%

QuickTime DV Encode and iMovie Effect are performed at the same time. Dual Processor machines rule the day

MP3 Encode + Photoshop Normal + Word Macro (Multitasking)

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Scores as percentage of Power Mac Dual G4/1 GHz	100%	33%	40%

The MP3 Encode, Photoshop Normal and Word Macro tests are all run at the same time

Gaming

Giants Highest Frame Rates

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Actual Frame Rates	105	31	38

Giants Average Frame Rates

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Actual Frame Rates	45	14.6	22

Giants Lowest Frame Rates

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Actual Frame Rates	21	7.6	10.7

4x4 EVO 2 Average Frame Rates- High Quality Setting

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Actual Frame Rates	18	8.6	14.5

4x4 EVO 2 Average Frame Rates- Medium Quality Setting

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Actual Frame Rates	30	16.5	21

4x4 EVO 2 Average Frame Rates- Low Quality Setting

Machine	Power Mac Dual 1 GHz	iMac G4/800 15 Inch Screen	iMac G4/1GHz 17 Inch Screen
Actual Frame Rates	42	22.5	31

For very demanding games you can't beat a Tower .. at least not yet