What is overclocking?

Transcription

1 Overclocking...

2 What is overclocking? Overclocking is process of running a computer component at a higher clock rate than it was designed for / specified by manufacturer Overclocking is performed on processors, video cards, motherboard chipsets, and Random Access Memory (RAM)

3 Why overclock? Increase performance of computer Can save money; buy lower-end component and overclock Overclock outdated components to keep up with new system requirements rather than buy new hardware Hobby for some people; push a computer to the limits

4 Why learn about overclocking? Helps understand more about the way a computer works Overclocking is relatively popular Alienware sells overclocked computers Something that you can theoretically try and might have fun with However, anything regarding overclocking is do at own risk and overclocking may void any warrenty

5 Overclocking Factors affecting overclocking Important for computer to remain stable when overclocked Cooling, voltage, architecture, and hardware limits Stability refers to capability of computer to perform tasks without error/failure Computer may become unstable if computer is overclocked too much Software used for overclocking OCCT: used to stress CPU/RAM to check for instability Core Temp: used to monitor temperature of CPU ClockGen / SetFSB: used to adjust clock speeds

6 Overclocking the CPU Intel CPU (AMDs a little different...) Overclocked via Front Side Bus settings and CPU multiplier Front side bus Controls communication between CPU, RAM, and PCI buses System clock gives speed of front side bus CPU multiplier Measures ratio of internal CPU clock to system clock (that controls front side bus, RAM speed, etc.) Higher the CPU multiplier --> higher CPU speed in relation to system clock

7 Overclocking Ways to overclock Using software such as ClockGen / SetFSB Using the system BIOs

8 Overclocking via Software Two options are ClockGen and SetFSB Overclocking via software makes it easier to test configurations and stress test without restarting PC Settings aren't permanent On some computers (such as Dells...) overclocking via software is the only option

9 Overclocking via Bios BIOS (Basic Input Output System) Allows computer user to control and tweak hardware De-facto standard for defining a firmware interface Originally stored on ROM chips that could not be altered, now typically stored using flash memory Advanced options that allow overclocking may be hidden ; may need to know specific key combination to retrieve options

10 Overclocking the Intel CPU/RAM Applies to both software and BIOs approach Note that it is easier to test using software approach since it is unnecessary to restart the computer each time Steps for overclocking Gradually increase the front side bus speed by a safe amount Increasing the front side bus overclocks both the CPU and RAM simultaneously Test the stability of the new settings using OCCT Monitor the CPU temperature using Core Temp while test running; overclocking may not be safe if temperature above 60o C Continue increasing front side bus speed until system instability detected by OCCT or CPU temperature becomes too high

11 What to do when system becomes unstable? Instability may be caused by CPU or RAM To determine location of instability, run OCCT testing only CPU and only RAM and see which test shows instability May be able to improve stability by increasing voltage of the CPU or RAM Not possible to do this on all computers (such as Dells) Increasing voltage may increase heat, so need to be careful to monitor temperature to prevent overheating

12 Benchmarking Results of overclocking may not be obvious Benchmarking allows the overclocker to see that the hard work actually did something Wikipedia: a benchmark is the act of running a computer program, a set of programs, or other operations, in order to assess the relative performance of an object, normally by running a number of standard tests and trials against it Gives measure to compare results with other overclockers Popular benchmarking programs Super PI Mod Calculates PI to a specified # of digits beyond decimal point 3DMark Runs graphical scenarios to test 3D capabilities of PC

13 Benchmarking Super PI Mod Computes PI to a user-specified number of digits past the decimal point Result: amount of time to took to generate the digits Will compute PI up to 32 million places past decimal Uses GaussLegendre algorithm to compute PI One of many methods to compute PI to many decimals Relatively fast Uses more memory than some other methods of computing PI

14 Benchmarking 3DMark Gives overall measure of computer system's 3D capabilities based on real-time 3D graphics and processor tests Tests both the CPU and graphics processing unit/video card Allows computer gamers to compare system capabilities as well as testing how overclocking will improve performance Used in overclocking competitions and records are recorded using this benchmark Video of benchmark running:

15 Benchmarking Records Hall of Fame giving the top performances according to various benchmarks from 3DMark:

16 Overclocking as Hobby/Competition Some overclock for practical reasons Others overclock for the sport of it... Equipment needed for serious overclocking Expensive motherboard with advanced settings (not like one in a basic Dell...) Cooling system to handle higher voltage Water/liquid cooling relatively common, used in Alienware computers Liquid nitrogen, liquid helium, and dry ice used in extreme cases such as record-setting overclocking attempts

17 Overclocking as Hobby/Competition Overclocking competitions One is the Gigabyte Open Overclocking Championship North American final held on April 25th, 2009 in City of Industry, CA World Championship held in Taipei, Taiwan on June 3rd Video from competition (note use of liquid cooling): Some results at the competition for different benchmarks...

18 Overclocking as Hobby/Competition Overclocking magazine:

19 Speed Record IBM and Georgia Tech got a chip to run at 500 Ghz Temperature dropped to -451 degrees Fahrenheit Chip can operate at 350 Ghz at room temperature Chip uses silicon-germanium technology, improvement over plain silicon Shows that silicon-based chips are far from performance limit Potential for use of these chips in commercial communications systems, defense electronics, space exploration, and remote sensing

20 Overclocking Video Game Systems Overclocking the Sega Genesis:

21 Underclocking Underclocking Opposite of overclocking Modifying system/cpu clock to run at a lower speed than specified Reasons for underclocking Decrease power consumption Less heat generated; allows computer to run more quietly without fan needed IPhone is underclocked in order to maximize battery life Iphone 3G contains a 833 Mhz processor underclocked to 600 Mhz