Hi,

Sorry if this is a bit of a basic question but my understanding is that the
smaller you can make the devices the faster potentially they can perform.
However there is a limit. Considering the speed of processors in PC's has
increased from 100MHz or so to 3GHz, what is the fastest speed that will be
attainable?

Charles Turner wrote:
> Hi,
>
> Sorry if this is a bit of a basic question but my understanding is that the
> smaller you can make the devices the faster potentially they can perform.
> However there is a limit. Considering the speed of processors in PC's has
> increased from 100MHz or so to 3GHz,

I've used PCs with x86 processors for 18 or 19 years and clock
speeds have gone up from 4 MHz to 3.6 GHz in that interval.


> what is the fastest speed that will be
> attainable?
>

I read something a few months ago about transistors running at
30 GHz in a lab. As to what we are likely to see outside of a
lab in the foreseeable future ???

And clock speeds aren't everything - I'll take a 2.4 GHz AMD64
chip over a 3.6 GHz Intel chip any day of the week.

Charles Turner wrote:
> Hi,
>
> Sorry if this is a bit of a basic question but my understanding is that the
> smaller you can make the devices the faster potentially they can perform.
> However there is a limit. Considering the speed of processors in PC's has
> increased from 100MHz or so to 3GHz, what is the fastest speed that will be
> attainable?

Well, that used to be the case upto and including the 130nm node, but
it's not the case as much anymore. There used to be a time when you
could take the same processor design, shrink it down by half, and you'd
also automatically be able raise clock speeds by double or more. That
was simply because the shrinkage would let the electrons travel shorter
distances. However, now due to quantum mechanical effects, the electrons
have a tendency to jump right out of their conductors, and that makes
them slower.

Yousuf Khan

On Wed, 23 Nov 2005 19:08:50 +0000 (UTC), "Charles Turner"
<(E-Mail Removed)> wrote:

>Hi,
>
>Sorry if this is a bit of a basic question but my understanding is that the
>smaller you can make the devices the faster potentially they can perform.
>However there is a limit. Considering the speed of processors in PC's has
>increased from 100MHz or so to 3GHz, what is the fastest speed that will be
>attainable?

Well Intel has completely backed away from their "expectation" of 10GHz by
the end of the decade and has taken a path which leads (back ?) to a CPU
which does more work per clock cycle. In fact they balked on the P4 at
4GHz... never happened at 90nm.

Here's an interview with Meyerson of IBM where he outlines the problems of
power density and leakage with recent 90nm geometry shrinks which have led
to the end of "classical scaling":
http://www.reed-electronics.com/elec...ticle/CA508575 and another
article on an IBM scientist who fills in the picture on the new importance
of materials:
http://www.reed-electronics.com/elec...icle/CA6281310

When you get down to geometry features in semiconductors which are a few
atoms thick, the laws of physics get in the way. Result: dual core CPUs.

--
Rgds, George Macdonald

On Wed, 23 Nov 2005 19:08:50 +0000 (UTC), "Charles Turner"
<(E-Mail Removed)> wrote:

>Hi,
>
>Sorry if this is a bit of a basic question but my understanding is that the
>smaller you can make the devices the faster potentially they can perform.
>However there is a limit. Considering the speed of processors in PC's has
>increased from 100MHz or so to 3GHz, what is the fastest speed that will be
>attainable?
>
>

No matter what it is, probably it will never be attained because it
will require certain compromises (waaaay longer pipelines, to name
just one) that hurt the performance more than you gain from raw Giga
hurts increase ;P
After all, what's the goal? Get into Guinness book with the top
number, or get the most performance from the existing technology,
preferably for less expenses? Even Intel finally got the
understanding, even though they preached the contrary for long, long
time.

NNN

(E-Mail Removed) wrote:
> On Wed, 23 Nov 2005 19:08:50 +0000 (UTC), "Charles Turner"
> <(E-Mail Removed)> wrote:
>
>> Hi,
>>
>> Sorry if this is a bit of a basic question but my understanding is that the
>> smaller you can make the devices the faster potentially they can perform.
>> However there is a limit. Considering the speed of processors in PC's has
>> increased from 100MHz or so to 3GHz, what is the fastest speed that will be
>> attainable?
>>
>>
>
> No matter what it is, probably it will never be attained because it
> will require certain compromises (waaaay longer pipelines, to name
> just one)

Intel thought they needed super long pipelines for the
architecture used by the P4s and the P4-Xeons. However, you
can't assume from that one rotten example of CPU architecture
that every CPU design will also require long pipelines in order
to reach the same clock speeds.

AMD, for example, has hit 2.8 GHz - twice the speed of the
initial 1.4 GHz P4's - with the AMD64 architecture and I have
seen an AthlonFX overclocked to 3.4 GHz using air-cooling.

On Thu, 24 Nov 2005 09:24:19 -0600, Rob Stow <(E-Mail Removed)>
wrote:

>Intel thought they needed super long pipelines for the
>architecture used by the P4s and the P4-Xeons. However, you
>can't assume from that one rotten example of CPU architecture
>that every CPU design will also require long pipelines in order
>to reach the same clock speeds.
>
>AMD, for example, has hit 2.8 GHz - twice the speed of the
>initial 1.4 GHz P4's - with the AMD64 architecture and I have
>seen an AthlonFX overclocked to 3.4 GHz using air-cooling.

I'm not sure that AMD is all that better off here than Intel. Their
Athlon64 FX chips from their 130nm production lines topped out at
2.6GHz. Their 90nm production line has thus far only managed to get
things up to 2.8GHz. I figure they'll probably clear 3.0GHz before
they're done, maybe up to 3.2GHz in about a years time, but not much
more out of 90nm. That's only a 23% increase in clock speeds,

-------------
Tony Hill
hilla <underscore> 20 <at> yahoo <dot> ca

In article <(E-Mail Removed)>, fammacd=!
SPAM^(E-Mail Removed) says...

> When you get down to geometry features in semiconductors which are a few
> atoms thick, the laws of physics get in the way. Result: dual core CPUs.

Actually, I think dual-cores came about because there wasn't
anything else interesting to do with transistors. Large caches were
the first useful transistor-sink but sooner or later, diminishing
returns bites hard. The next obvious place to absorb transistors
was another core.

At least that was my proposal here, oh, about the turn of the
century. ;-)

--
Keith

Keith wrote:
> In article <(E-Mail Removed)>, fammacd=!
> SPAM^(E-Mail Removed) says...
>
>> When you get down to geometry features in semiconductors which are a few
>> atoms thick, the laws of physics get in the way. Result: dual core CPUs.
>
> Actually, I think dual-cores came about because there wasn't
> anything else interesting to do with transistors. Large caches were
> the first useful transistor-sink but sooner or later, diminishing
> returns bites hard.

Within an unlimited transistor budget I would be dreaming about
several gigs of on-chip RAM - skip the L2 and off-chip RAM
completely. I have images of a chip so big that you put in on
the /other/ side of the motherboard ...

And I think of the "other side of the motherboard" idea in the
context of "ordinary" CPUs as well. Imagine if the left side of
a tower or mid-tower case was a single, huge passive heat-sink
and your motherboard was attached directly to it - no intervening
back plane - with the processor(s) firmly clamped between the
motherboard and the case-panel/heatsink.

> The next obvious place to absorb transistors
> was another core.
>
> At least that was my proposal here, oh, about the turn of the
> century. ;-)
>

On Thu, 24 Nov 2005 23:35:33 -0600, Rob Stow <(E-Mail Removed)>
wrote:

>And I think of the "other side of the motherboard" idea in the
>context of "ordinary" CPUs as well. Imagine if the left side of
>a tower or mid-tower case was a single, huge passive heat-sink
>and your motherboard was attached directly to it - no intervening
>back plane - with the processor(s) firmly clamped between the
>motherboard and the case-panel/heatsink.

Something like the Zalman heatsink that was a casing I saw somewhere
before? Heard it was a major PITA to install/uninstall anything :P

--
A Lost Angel, fallen from heaven
Lost in dreams, Lost in aspirations,
Lost to the world, Lost to myself