Replacing motherboard timing crystals?

[HarryBeanbag]

The question concerning cpu clock cycles. If a ic chip or eletrical circut is meant to perform a given number of operations per clock cycle,

and the clock cycles are determined by the oscillation of a timing crystal, then what would the effects be of swapping in a more rapidly

oscillating crystal?

The ic chips would be process the same work per clock cycle , however the clock cycles occur more frequntly allowing a performance


increase?

Please Comment,

anyone no anything about this stuff?

electrial circuts in general

 

[CTho9305]

its called overclocking

except, the method you propose has some negative aspects. with regular "modern" overclocking, you set the PLL to multiply the base frequency differently. So, you see a higher MHz listed... the computer "knows" it's running faster.

Your method would not be detectable by the computer itself. it would report standard speed, but would run faster, and the clock would be faster, etc. It would probably cause trouble if you have cards that have their own crystals... like network/video cards. either way, you might get network problems since stuff needs to be sync'ed.

 

[jamarno]

The only things that will likely be affected are the real-time clock (I don't know if it's derived from the master oscillator or uses the absolute time clock for its heartbeat) and any CGA video card (only if using composite video output for color). Other devices shouldn't be affected, especially if they have their own crystal oscillators.

 

[blahblah99]

Replacing the mb with faster crystal won't work because those ICs are designed to work at that maximum frequency. If the clock frequency was faster than from what it's suppose to be, you'll run into problems at the transistor levels where the parasitic and junction capacitances start to affect the performance.

 

[zephyrprime]

<< Replacing the mb with faster crystal won't work because those ICs >>


This obviously is incorrect since people successfully overclock their computers all the time.

Replacing the crystal is the way people used to overclock the 8086 way back in the old days. I believe that this eventually lead to computers with the turbo button so that you could choose between overclocked and regular at the push of a button. Eventually, the turbo setting became the default non-overclocked setting and the non-turbo setting just uselessly slowed to computer down.

 

[HarryBeanbag]

I know this is an outdated method of overclocking, but I was curious if it still may work with todays hardware. As for creating problems with periferals, those cards all have thier own crystals and don't depend on timing from the motherboard, and any network sync is done by the nic.

My root question is; are there any electronic engineers out there who would be willing to try something like this?

 

[CTho9305]

uh... well, I know I can overclock about 10% without issues. the base crystal is 14.something MHz, so if you send me a ~15.4 MHz one, I guess I could try. I have some 20MHz ones from old NICs, but 42% is more OC than my setup does

actually... I'd rather my k7v stay in-tact. the newest machine I could do would be socket 5 or socket 7, with a p75 or p133, most likely