Welcome computer overclockers.

INFORMATION ON OVERCLOCKING

This page is for those of you who are considering overclocking your computer. It will contain information that I have gathered from my own "studies," and links to sites where this is covered in much more detail. First off lets answer the question, what is overclocking? Overclocking is the practice of running your computers cpu faster than it was rated by the manufacturer. This can be done by one of two ways. Method one is to overclock by changing the motherboard's jumpers to reflect a higher speed cpu; for example, a 166mhz gets its speed rating by being clocked at a 66mhz bus speed times a 2.5 clock multiplier. 66x2.5=166 If you change the multiplier to 3 the motherboard will default to a 200mhz setting. 66x3=199.9mhz This used to be how overclocking was done; but due to the practice of resellers remarking the chips to higher speed ratings and selling them as real "200mhz" cpu's, for example, intel has gone to the practice of "clock locking" multiplier settings for all of their cpu's. That leaves method two which is to "overbus" or to run a cpu at a higher bus speed than it was rated for. Lets take our trusty 166mhz cpu above and overbus it. 2.5x66=166 or 2.5x75=188 or 2.5x83=207 or even 2.5x100=250 Of course your motherboard would have to support these settings to be of any of use, and of course not all cpu's will work at these bus speeds.

Why overclocking? Why not just buy the fastest part? Money. A 400mhz pentium II today costs about $550 A Celeron 266 overclocked to 400mhz costs $76 Speed difference? 5%, if that. Is overclocking for everyone? Nope.

Overclocking may increase the chances of your system being less stable. If your are uncomfortable with this, by all means stop reading now. One problem with overclocking is heat. To get your cpu running at higher speeds it may be necessary to boost the voltage going to the cpu, which of course generates more heat so a good fan/heatsink combo is a must. Also some other componants like video cards generate lots of heat and can make your system unstable. There is no such thing as too much cooling in the computer world. Cool componants equal stable and long lived parts. Other problems when overbussing is other components like your video card or even hard drive may not work at the higher bus speeds, damage to them could occur.

Here are some examples of successful overclocked computers I have owned, and one failure. Number 1. A pentium 150 classic (non-mmx) overbussed to 188mhz for over a year before upgrading. Number 2. A pentium 233MMX overbussed to 262mhz for a year before upgrading. Number 3 and current pc. A Celeron 266 running at 400mhz. The one failure was a 4 year old 486/50 that was overbussed to 66mhz. The chip failed after 2 weeks. Of course the cpu was 4 years old and had no fan to help cool it down-still it cost little to replace the chip and put the machine right again.

As you can see I like cases that really keep things cool. The fan on the right is 5 inches across and moves 90cfm of air.

Motherboard Abit BH6 CPU Celeron 266 running at 400mhz (4x100bus) 128megs PC-100 ram 2.0 gig Western Digital harddrive (master) 5.2 gig Maxtor harddrive (slave) Creativelabs 32X CD-ROM Sony 2x8 CD-ROM recorder Diamond G-460 AGP video card (i740 based) Digital PCI network card Ensonic Audio PCI sound card Metabyte Wicked 3d VoodooII 12 meg US Robotics 56k modem Adaptec 1505 SCSI flatbed scanner interface card Mitsubishi Diamond Star 20" monitor

BENCHMARKS QuakeII at 640x480 Voodoo II card Demo 1- 74 FPS QuakeII at 640x480 with i740 card opengl Demo 1- 40 FPS QuakeII at 640x480 with Voodoo I Demo 1- 27 FPS GlQuake at 640x480 with Voodoo II 103 FPS! More benchmarks soon..

LINKS TOMS HARDWARE http://www.tomshardware.com/ Anand's Hardware Tech Page http://www.anandtech.com/ The Computer Hardware Performance Page http://www.cam.org/~agena/computer.html Overclockers' Workbench http://come.to/overclock The Unofficial Abit BX6 / BH6 Page http://bxboards.pair.com/ Newsgroups comp.sys.pc.hardware.video comp.sys.pc.hardware.chips alt.comp.hardware.overclocking

I have run this as fast as 448mhz (4x112bus) sick. not bad for $76 My first Pentium computer was a 133mhz. The CPU was $400 by itself back in the day..