Computer clock speeds

[W1GUH]

My head starts spinning when I try to think about clock speeds in the multiple GHz range, especially when I remember way back when it was difficult sometimes to get a 40 meter xtal oscillator to oscillate!

So...how do computers do it? #With a tiny crystal someplace? #On board an IC or external?

[ab1ga]

Those chips do a lot of on-chip frequency multiplication. The active devices are very small, so transit time effects that limited maximum operating frequency are much lower. And design software has made it possible to design the circuitry using transmission line techniques, even within the silicon structure.

The chip industry is an great example of progress not through a big event, but through a long series of small advancements.

[W1GUH]

Quote[/b] (ab1ga @ June 24 2007,15:50)]Those chips do a lot of on-chip frequency multiplication. The active devices are very small, so transit time effects that limited maximum operating frequency are much lower. And design software has made it possible to design the circuitry using transmission line techniques, even within the silicon structure.

The chip industry is an great example of progress not through a big event, but through a long series of small advancements.
Outstanding technology you share there...guess I should digest that. Thanks!

[K8ERV]

I find it amazing that the clock freq is now higher than that of my microwave oven.

Tom K8ERV Montrose Co.

[kl7aj]

Quote[/b] (K8ERV @ June 27 2007,12:14)]I find it amazing that the clock freq is now higher than that of my microwave oven.

Tom K8ERV Montrose Co.
And your processor probably runs HOTTER!

[KI4MRU]

Of course, as we have seen lately, it's not "all about the gigahertz." Many of the new Intel Core 2 processors run slower clocks (and consequently cooler temperatures) than Pentium 4 and Pentium D chips did, but outperform those older chips through more efficient pipelining, caching, etc. While clock speed is an important component to consider, it's no longer the absolute benchmark for overall system performance that it used to be. I took two semesters of computer architecture, and became more amazed than ever that these insanely complex devices actually work.

[WA7KKP]

You've got it -- there's a small Xtal oscillator on the motherboard that is the drummer for all of the band in silicon . . . Later processors have it built into the cartridge.

Harmonics actually clock the processor -- it is very difficult to get a crystal to oscillate over 150 MHz or so. Part of the mobo setup is setting the multiplier for the processor used.

Gary WA7KKP

[ka5piu]

Hello.


Correct, a master clock provides reference.
This is a module all itself.
Remember the TV color burst? 3.579545 Hz.
I thought very little of the high precision reference oscillator in the FT-897D, so, with one of the original standard oscillator in hand, I produced a true high stability oscillator.
Now, I get 8 Hz of drift at worst case.
I used one of the ultra high precision units.
http://www.foxonline.com/
There are 2 other fixed oscillators in the radio that also got replaced for this level of precision along with 2 voltage regulators that were added.
But, the point being, due to the need for precision timing at mass production one can get an entire buffered ultra high precision pure sinewave oscillator at a good price.
http://foxonline.com/ocxoindx.htm

[W1GUH]

Quote[/b] (KI4MRU @ June 28 2007,20:21)]Of course, as we have seen lately, it's not "all about the gigahertz." #Many of the new Intel Core 2 processors run slower clocks (and consequently cooler temperatures) than Pentium 4 and Pentium D chips did, but outperform those older chips through more efficient pipelining, caching, etc. #While clock speed is an important component to consider, it's no longer the absolute benchmark for overall system performance that it used to be. #I took two semesters of computer architecture, and became more amazed than ever that these insanely complex devices actually work.
You and me both, and I've made a living off of designing those things for the last 37 year, both hardware and software.

I worked for DEC back in the complex instruction set days, and the way the architected the virtual memory was just amazing. #I finally, sorta, got it...but it took me a few time through the tech manual to do that. # I was in hardware in those days, and that was the first mini to use semi-custom LSI gate arrays. #

But that machine is now a simple toy compared with the PC's were using. #Whatever else there is to say about Windows and 'net technology...it's complexity and speed are unreal.