Low End Mac's Online Tech Journal

AltiVec vs. Pentium III

A Little Bad Math Goes a Long Way

Dan Knight - 2000.11.21

If there's one thing that gets my goat, it's bad math and statistics.

In Gauging the Gigaflops Gap, Don Granberry of ZDNet tries to explain how the G4 with AltiVec is superior to the Pentium III. It's actually a fairly accessible explanation, but the numbers are flawed.

Granberry uses the following table to compare a 700 MHz PIII with a 500 MHz G4:

It's a nice table. It's clearly labeled. The facts are clearly established. But there's one piece of misleading data: CPU speed doesn't mean a thing when you're looking at how many clock cycles are used.

MHz for MHz, the G4 is 3.68 times more efficient at these particular functions (or, as Granberry puts it, the G4 does the same work in 27% as many processor cycles).

This wouldn't be a problem, except that later in the article he links clock speed to this. Which wouldn't be a problem, except that he doesn't apply the same clock speed to both processors.

Multiplying 3.68 by 700 MHz, Granberry states that a 2.6 GHz Pentium III would match the performance of a G4/500 on these tests - but it just isn't so.

The problem is the misleading data (remember how story problems would sometimes introduce numbers that were not necessary to solve the problem?) brought him to the wrong number. No matter how precise the math, if you're multiplying the wrong number, you get the wrong result.

Instead of 2,576 MHz, he should have multiplied 3.68 by 500 MHz, resulting in a Pentium III running at 1,840 MHz to match the G4/500's performance on these particular functions.

Of course, Apple is now shipping the Power Mac G4/500 in a dual-processor configuration, so it would take 3,680 Pentium III MHz to match it. For the sake of convenience, let's say a quad-processor PIII/900 system would match the dual-processor G4/500 on these vector functions.

Whether this means much in the real world is another question entirely, but at least we have the math right.

Join us on Facebook, follow us on Twitter or Google+, or subscribe to our RSS news feed

Today's Links

Recent Content

About LEM Support Usage Privacy Contact

Low End Mac is an independent publication and has not been authorized, sponsored, or otherwise approved by Apple Inc. Opinions expressed are those of their authors and may not reflect the opinion of Cobweb Publishing. Advice is presented in good faith, but what works for one may not work for all.
  Entire Low End Mac website copyright ©1997-2016 by Cobweb Publishing, Inc. unless otherwise noted. All rights reserved. Low End Mac, LowEndMac, and lowendmac.com are trademarks of Cobweb Publishing Inc. Apple, the Apple logo, Macintosh, iPad, iPhone, iMac, iPod, MacBook, Mac Pro, and AirPort are registered trademarks of Apple Inc. Additional company and product names may be trademarks or registered trademarks and are hereby acknowledged.
  Please report errors to .
  LINKS: We allow and encourage links to any public page as long as the linked page does not appear within a frame that prevents bookmarking it.
  Email may be published at our discretion unless marked "not for publication"; email addresses will not be published without permission, and we will encrypt them in hopes of avoiding spammers. Letters may be edited for length, context, and to match house style.
  PRIVACY: We don't collect personal information unless you explicitly provide it, and we don't share the information we have with others. For more details, see our Terms of Use.

Follow Low End Mac on Twitter
Join Low End Mac on Facebook

Page not found | Low End Mac

Well this is somewhat embarrassing, isn’t it?

It seems we can’t find what you’re looking for. Perhaps searching, or one of the links below, can help.

Recent Posts

Most Used Categories

Archives

Try looking in the monthly archives. :)

Tags

802.11g 802.11n 68030 68040 Apple April Fools clamshell iBook Classic Mac OS FireWire FireWire 400 G3 humor iBook iMac iMac G3 Intel iOS iPad iPhone LaserWriter Linux Mac MacBook Air Mac clones Mac mini Mac OS 9 macOS Sierra Mac OS X Mac OS X 10.4 Tiger Mac OS X 10.5 Leopard Microsoft OS X 10.6 Snow Leopard OS X 10.7 Lion OS X 10.8 Mountain Lion OS X 10.9 Mavericks OS X 10.10 Yosemite OS X 10.11 El Capitan Performa PowerBook PowerPC Rodney O. Lain SCSI Thunderbolt USB 1.1 USB 2.0
Page not found | Low End Mac

Well this is somewhat embarrassing, isn’t it?

It seems we can’t find what you’re looking for. Perhaps searching, or one of the links below, can help.

Recent Posts

Most Used Categories

Archives

Try looking in the monthly archives. :)

Tags

802.11g 802.11n 68030 68040 Apple April Fools clamshell iBook Classic Mac OS FireWire FireWire 400 G3 humor iBook iMac iMac G3 Intel iOS iPad iPhone LaserWriter Linux Mac MacBook Air Mac clones Mac mini Mac OS 9 macOS Sierra Mac OS X Mac OS X 10.4 Tiger Mac OS X 10.5 Leopard Microsoft OS X 10.6 Snow Leopard OS X 10.7 Lion OS X 10.8 Mountain Lion OS X 10.9 Mavericks OS X 10.10 Yosemite OS X 10.11 El Capitan Performa PowerBook PowerPC Rodney O. Lain SCSI Thunderbolt USB 1.1 USB 2.0

Favorite Sites

MacSurfer
Cult of Mac
Shrine of Apple
MacInTouch
MyAppleMenu
InfoMac
The Mac Observer
Accelerate Your Mac
RetroMacCast
The Vintage Mac Museum
Deal Brothers
DealMac
Mac2Sell
Mac Driver Museum
JAG's House
System 6 Heaven
System 7 Today
the pickle's Low-End Mac FAQ

Affiliates

Amazon.com
The iTunes Store
PC Connection Express
Macgo Blu-ray Player
Parallels Desktop for Mac
eBay

Low End Mac's Amazon.com store

Advertise

All of our advertising is handled by BackBeat Media. For price quotes and advertising information, please contact Page not found | Low End Mac

Well this is somewhat embarrassing, isn’t it?

It seems we can’t find what you’re looking for. Perhaps searching, or one of the links below, can help.

Recent Posts

Most Used Categories

Archives

Try looking in the monthly archives. :)

Tags

802.11g 802.11n 68030 68040 Apple April Fools clamshell iBook Classic Mac OS FireWire FireWire 400 G3 humor iBook iMac iMac G3 Intel iOS iPad iPhone LaserWriter Linux Mac MacBook Air Mac clones Mac mini Mac OS 9 macOS Sierra Mac OS X Mac OS X 10.4 Tiger Mac OS X 10.5 Leopard Microsoft OS X 10.6 Snow Leopard OS X 10.7 Lion OS X 10.8 Mountain Lion OS X 10.9 Mavericks OS X 10.10 Yosemite OS X 10.11 El Capitan Performa PowerBook PowerPC Rodney O. Lain SCSI Thunderbolt USB 1.1 USB 2.0
at BackBeat Media (646-546-5194). This number is for advertising only.

Open Link