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What Effects Computer Speed Most: CPU, Software Extensions, or Backside Cache?

Researched by Sam J. 



The purpose of this experiment was to find which element affects the computer’s speed most.

I became interested in this idea when I found, on the Powerlogix website, that the CPU was capable of being modified.

The information gained from this experiment will make computer buyers more able to find the best upgrade for them.



My hypothesis is the CPU will make the most difference in speed.

I base my hypothesis on information gained from computer magazines saying that the CPU is the "brain" of a computer.

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The constants in this study were: the computer, the test program, the system software, the monitor, the test suite, and the desk on which the computer was located.

The manipulated variables were: the speed of the CPU, the speed of the cache, and the system extensions.

The responding variable was the speed of the computer.

To measure the responding variable I made a suite (not necessary, just saves time) inside the "MacBench" speed test program and then ran it.  
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1 PowerBase 200 with voodoo card and Powerlogix 220 G3
1  Testing program
1 monitor
1 keyboard
1 System extension called "LibMoto"
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1.    Choose which element to modify (a= cpu, b= cache, c= extensions, d= control), making sure that "LibMoto" is turned off in the extensions control panel and the cache is off in "Cache Control" 
2a.   Unplug everything from the computer after shutting it down. 
2b.  Boot a program called "Cache Control" 
2c.  Boot the extensions control panel. 
2d.  Skip to step 11 
3a.  There are four thumbscrews on the back of the computer.  Unscrew them. 
3b.  Click the button entitled "Enable Backside cache".  If there is no button like this, skip to step 11. 
3c.  Use the standard set of extensions, with "LibMoto" added to the list 
4a.  Pull the computer case towards you and then up so it slides off. 
4c.  Quit the extensions control panel 
5a.  Gently set the computer on its side so that you can see into it. 
5c. Skip to step 11 
6a. Find the CPU card.  It is beside a very large slot. 
7a. Find the green switch that is by itself and turn it from five to seven. 
8a. Close up the computer.  Do NOT press the motherboard reset button, no matter what the Powerlogix manual tells you, or you will have to unplug and then plug in every cord for your computer to start up. 
9a. Re-plug everything into your computer. 
10a. Start your computer 
11. Do steps 14-16 
12. Boot MacBench 
13. Run tests on publishing graphics, graphics, CPU, and FPU 
14. Shut down your computer 
15. Wait five minutes (to clear RAM) 
16. Start your computer 
17. Repeat steps 12 and 13 
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The original purpose of this experiment was to find out which of the following elements affected speed most: the CPU, the cache, or the system folder’s extensions.

The results of the experiment were that the cache was the highest score  and the CPU was the lowest score.

See the table and graph below. 

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My hypothesis was that the CPU would be the largest factor for performance. 

The results indicate that this hypothesis could be either accepted or rejected.  The reason being that the CPU speed was only modified by forty megahertz, just a tiny fraction of what you could if you actually put in a processor upgrade.  However, my hypothesis could be rejected because the results show that the cache had the highest rating.

Because of the results of this experiment, I wonder if it would be the same results if I ran the tests on a different computer. 

If I were to conduct this experiment again I would boost the clock speed of the CPU much more. 
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 Computers are more a part of the modern human life than we think.  Modern communities could not run well without computers.  Computers build cars on an assembly line, monitor the security systems of the most essential US military bases and embassies, and process information from the SETI site, to name a few jobs.  Recently, the Y2k bug has shown us just how important computers are. 

Essential Components

 A computer’s internal components make it operate.  When you press the power button, the ROM, permanent memory used for the basic startup instructions (read only memory), tells the CPU, the processor in the "heart" of a computer that does all the thinking of a computer, to look for a system folder in all the information buses (a sort of highway for information).  When it finds one, the computer follows the instructions that were stored in the folder.  When the computer finishes booting up, it looks for other devices and puts them on the desktop of the computer.  RAM then activates, storing the information that was not stored on the permanent storage devices such as a hard drive.  RAM is a device that lets a program remember what it has done, while erasing when it loses power.  Carrying all this information is the system bus, the main information highway of a computer.  Without it, a computer would be like a human without a spinal cord.  In other words, it could not do anything. 

Control Devices

 A computer needs components to help make it understand what the user is trying to make it do, and vice versa.  The monitor is a device that shows pictures telling the user what is happening in the computer.  A mouse lets the user control what the computer is doing by using a ball on the bottom of a plastic container with the bottom of the ball sticking out onto the mousepad.  When the ball is moved, the computer senses it and moves the pointer on the screen.  A trackball is similar to a mouse, but does not need a mousepad and the user moves the pointer by sliding his/her hand across the large ball in the center of the device.  Touchpads use the user’s finger to move the pointer.  The user slides his/her finger across the pad while the computer tracks the movement of pressure. 

Storage Devices

 When a user saves a document, it saves into storage devices.  There are several main groups of devices used for data storage.  One is a CD  (compact disc)/ DVD (digital videodisc), which uses holes burned into a removable disc to record information.  Another is a hard disc, using a disc to permanently store data in a rewriteable format.  The floppy drive family uses a removable disc housed in a plastic protective container. 

Types of the Computer

 The computer is used in many more ways than one.  The personal computers are used for work, typing, and play.  They have large hard drives built into them to store many games and nice processors built to play them.  Industrial computers are built to do repetitive tasks such as building cars and monitoring security systems.   They are the cheapest computers. Supercomputers are built to do the hard jobs.  They design cars and then test-drive them, simulating nuclear blasts, and computing to the last number the value of p.  They are the fastest possible. 

What Affects a Computer’s Speed

 There are many things that affect a computer’s speed.  These are just about 60% of them, but these are 95% of the main factors.  First, there is the CPU.  The CPU’s power greatly affects a computer’s speed because the CPU does all the core processing and also tells everything what to do.  Another element that affects speed is the system bus because the system bus carries all the information during startup and when the computer is running.  Also, the program the computer is running affects speed because if the program was a Mac-PC hybrid, the Mac will usually run it slower because it will be built for the PC.  Also, there is the factor of the graphics processor.  In some games, 3DFx processors will enhance graphics and take some of the load off the CPU.  The speed of your hard disc will affect the speed of the computer because when you boot up a program, it reads off the hard disc and loads it into the computer.  You cannot run any programs without a hard disc.  If you are running a program off the internet, you will need a fast internet server to load the game before you go to sleep (in most cases) or go off to do some other thing and the internet connection fails after it finishes downloading.  Also, you need the right plugins for your computer to run some programs quickly.  Without the right plugins, your computer could not run most programs newer than 1995.  The speed of the RAM bank also counts, too.  When you start a program that is relatively advanced and requiring, you need fast RAM because it is faster because it is faster to load something that you did in a game, like saving, when you have fast RAM.  Another thing that affects the speed is the size of your RAM bank.  When you run advanced programs, those programs usually suck up RAM.  For instance, "Unreal Tournament" requires 95 MB of RAM as a minimum to run without crashing after about 15-30 minutes.

Types of CPUs

 There are many types of CPUs.  There are IBM, Motorola, Apple, and Intel chips. The two main types are Macintosh chips and PC chips. All the Macintosh chips listed here are from 1984 or later and all the Intel chips are from 1995 or later.  Macintosh chips are generally the faster of the two.  There are two kinds of Macintosh chips.  One is the 680x0 family, and the other is the PowerPC chips.  680x0 chips are the older, slower chips, stopped being made in 1995.  They are: the 68000, the original chip, the 68020, the rarest chip in all of Macintosh history, the 68030, used most commonly of all the chips, the 68040, fastest of all, and the 68LC040, a sort of stripped 68040.  The other is the PowerPC family of chips, incorporating the new RISC processing algorithm, which is the fastest of all the families.  They are: the 601, the original PowerPC chip, the 603, the slowest of all the PowerPC chips, the 603e, the second slowest, the 604, the fourth fastest, the 604e, the fastest of all chips before the Gxs, the G3, second fastest chip, and the ultra-powerful G4, the fastest chip in the history of all computing.  The Intel chips are: the Pentium, the Pentium II, the Pentium III, the Celeron, and the AMDk62 processor. 


 A computer is certainly a big help to most people that have one, especially businesses.  It is a complex, delicate thing, and without any one of its components it would be useless.  Computers operate almost all of our businesses, in part.  Modern society could not advance without computers. 
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Tuesday, November 3

Used whole book 
No volumes 
I used the whole magazine 
November 1998

"Microprocessor, 680x0" 
Microsoft Encarta 
Volume One 
No pages in encyclopedia

The Usborne Computer Directory for Beginners 
Unknown publishing place 
Doesn’t say the date published 

Usborne Electronic World  
Usborne Guide to Computers 
Published in London 


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