How Many Processor Cores Are Enough?
|
From: ranjit_mathews@yahoo.com on 10 Oct 2006 13:01 Nick Maclaren wrote: > In article <1160496420.908302.5740(a)b28g2000cwb.googlegroups.com>, > "ranjit_mathews(a)yahoo.com" <ranjit_mathews(a)yahoo.com> writes: > |> > |> > |> > |> If your competitor ships a computer with a 1.6GHz processor and > |> > |> DDR2-533 RAM and you figure that they can get their processor to run at > |> > |> 3.2Gz by the time DDR3-1066 RAM becomes mainstream, you know they'll be > |> > |> able to compress or run a DOM parser about twice as fast, don't you? > |> > > |> > No. > |> > |> It would be "no" only if you have some sure-fire way of determining > |> that your competitor is incapable of scaling up all the parts in their > |> system along with the processors they use. > > No, it wouldn't. Read what YOU said. "You know they'll" is short for > "you know they will" and not "you cannot be sure that they will not". I said "you know they will be able to", not "you know they will". They might be able to and still not do it, but you rarely can know that they won't be able to.
From: Tim Bradshaw on 10 Oct 2006 13:00 On 2006-10-10 17:33:57 +0100, "ranjit_mathews(a)yahoo.com" <ranjit_mathews(a)yahoo.com> said: > The components that need to go faster are the ones that matter to the > problem at hand. If the ones that matter to a given problem are the > processor, RAM and communication links between processors, then if you > maintain a constant ratio of speed of RAM to the speed of those other > components, you can make them go faster. Which you can't do. > > If you can keep their latencies constant when measured in ticks (a unit > of time that changes in inverse proportion to frequency), Which you can't do. --tim
From: ranjit_mathews@yahoo.com on 10 Oct 2006 13:26 Tim Bradshaw wrote: > On 2006-10-10 17:33:57 +0100, "ranjit_mathews(a)yahoo.com" > <ranjit_mathews(a)yahoo.com> said: > > > The components that need to go faster are the ones that matter to the > > problem at hand. If the ones that matter to a given problem are the > > processor, RAM and communication links between processors, then if you > > maintain a constant ratio of speed of RAM to the speed of those other > > components, you can make them go faster. > > Which you can't do. Can you think of any component that has reached its maximum performance or lowest latency and will never again get faster or snappier? If not, then you can. All you do is to hold off on speed or latency improvements to some components till you've got ready to speed up all of them (or a certain subset of them) in synch. > > If you can keep their latencies constant when measured in ticks (a unit > > of time that changes in inverse proportion to frequency), > > Which you can't do. Can I not get DDR-333 with the same timings (measured in memory bus cycles) as typical timings for DDR-266? Latency to L1 cache takes more ticks when I clock a processor faster? Latency of 1GHz hypertransport is not lower than for 800MHz HTT? > > --tim
From: Tim Bradshaw on 10 Oct 2006 13:41 On 2006-10-10 18:26:54 +0100, "ranjit_mathews(a)yahoo.com" <ranjit_mathews(a)yahoo.com> said: > Can you think of any component that has reached its maximum performance > or lowest latency and will never again get faster or snappier? If not, > then you can. All you do is to hold off on speed or latency > improvements to some components till you've got ready to speed up all > of them (or a certain subset of them) in synch. Why yes, I can. c has been constant for billions of years, and there's no evidence at all that it will increase any time soon.
From: Nick Maclaren on 10 Oct 2006 14:27
In article <eggm0q$k2l$1$8300dec7(a)news.demon.co.uk>, Tim Bradshaw <tfb(a)tfeb.org> writes: |> On 2006-10-10 18:26:54 +0100, "ranjit_mathews(a)yahoo.com" |> <ranjit_mathews(a)yahoo.com> said: |> |> > Can you think of any component that has reached its maximum performance |> > or lowest latency and will never again get faster or snappier? If not, |> > then you can. All you do is to hold off on speed or latency |> > improvements to some components till you've got ready to speed up all |> > of them (or a certain subset of them) in synch. |> |> Why yes, I can. c has been constant for billions of years, and there's |> no evidence at all that it will increase any time soon. Actually, we have no proof of that :-) But, if Ranjit Mathews is relying on be able to change the speed of light, or to shrink transistors below the size of a single atom, he may have a few technical problems in doing so .... Regards, Nick Maclaren. |