141–150 of 180 posts
So, what was the reason CPUs could not scale vertically (higher frequency)? Temperature? Stability?
Over a decade later, even overclockers haven't managed to reach 10GHz --- but some have come close: http://www.tomshardware.com/news/amd-fx-8150-overclock-9ghz-... At 10GHz, light travels approximately 3cm between each period of the clock. Note that transistors which operate above 10GHz are not rare and used in microwave applications; as I understand it, the difficulty is in creating logic circuits with them and at a…
> 10GHz, light travels approximately 3cm between each period of the clock Light doesn't change speed, so this statement confuses me.
Practically speaking, it does change speed. The speed of light in a vacuum is fixed, but it varies based on what it's traveling through.
The propagation velocity of an EM signal in RG coax cable is 80% of c*, PCB traces can be as low as 50% and somewhat surprisingly both fiber optic cable and cat6 cable are about the same, ~60-70%. I don't know if there is any good public information about the velocity factor with modern CPU transmission lines.
Earlier quoted context omitted.
> Although the transistors can technically run at 9 GHz, the resulting power density is very difficult to cool. But nowadays we have processors with multiple cores, where sometimes you need only 1 core (and it needs to be fast). So would it be an idea to increase clock frequency for those cores, but multiplex them quickly to allow them to cool?
Nope. It is not just thermals but also memory latency. If you have four cores and each has two register files you can get 8x the bandwidth at the same latency. That 10GHz talk was a lie on the part of Intel to intimidate people away from AMD, not only would a 10GHZ P4 melt down, but it would be stalled all the time from memory latency. So many things did not work that it was not an honest mistake. Today there is talk…
Earlier quoted context omitted.
The general term for that is Dark Silicon [1]. It helps a little and as, others have pointed out, Intel CPUs already have a similar feature called "Turbo Boost." NVIDIA processors also have a similar "GPU Boost" feature. But I don't know if that can enable a single core to run at 10GHz. Shutting off other cores does not lower the local power density / thermal dissipation of the single core at 10GHz. You still have to…
Right, but the suggestion is that when "one core" is running, you switch around which core it is that's actually hot, so they're taking turns generating the heat. Obviously there's some cost there in sharing registers, cache, etc, but it's an interesting notion.
Earlier quoted context omitted.
We had people in the office in the late 90s with repetitive stress issues who were using Dragon NaturallySpeaking pretty effectively.
But where have the repetitive stress issues gone?
Earlier quoted context omitted.
Is this really the experience of voice recognition people have? I can't get Siri to reliably create appointments... takes about 3 tries for the voice recognition to work correctly.
On Android, it has worked well for me for simple things (e.g. "Remind me to take my laundry off the hanger tomorrow at 15:00"). Have not tried anything fancy, though. A coworker once told his smartphone, "Tell me a dirty joke". It kind of worked, it opened a web search for "dirty joke". Cortana really impressed me by actually telling a joke; it was about dirty laundry (but I suspect that was intentional to avoid offe…
It works wonderfully well. I use it obsessively to the point that people now joke that if you ask me a question I'll simply ask Google about it.
I remember reading this news (and perhaps even this exact article - it certainly feels familiar) back when it was released and being so excited as a 15 year old gaming nerd. It really was a time when stuff was changing so rapidly - and those changes were resulting in massive, really obvious performance gains - that you couldn't help but just look forward to where it might go if the pace continued. Everything was abou…
tl;dr: Core i7-2600k @ 3GHz, is about 2,67x faster than a Pentium 4 HT 660 (Prescott ua) @ 3Ghz. In the benchmark they tested single core, and equal clock, to keep everything as level as posible.
As for single core performance, Kaby Lake would be between 30 to 40% better than Sandy Bridge (which could be called the peak improvement architecture in the Core i brand), so it'd be about ~3,5x faster than the Prescott based chips.
Over a decade later, even overclockers haven't managed to reach 10GHz --- but some have come close: http://www.tomshardware.com/news/amd-fx-8150-overclock-9ghz-... At 10GHz, light travels approximately 3cm between each period of the clock. Note that transistors which operate above 10GHz are not rare and used in microwave applications; as I understand it, the difficulty is in creating logic circuits with them and at a…
Earlier quoted context omitted.
Right, but the suggestion is that when "one core" is running, you switch around which core it is that's actually hot, so they're taking turns generating the heat. Obviously there's some cost there in sharing registers, cache, etc, but it's an interesting notion.
I see, that is an interesting notion. But how do you "share registers" at 10 GHz, without massive stalls during context switches? The suggestion seems require that the cores are separated by some considerable physical distance, in order to allow for heat dissipation. However this distance also means that data sharing between the cores would be slow and also very power intensive in itself. I'm not a chip designer thou…
If performed at the hardware level, you may also get some improvement by having the core push its register and low level cache state directly to the next processor, rather than have them pull the data through shared cache or RAM. Unlike a typical context switch, the process is not being resumed from idle, but has an active cache state.
Just to give a little intuition for exactly how fast your CPU runs (assuming ~3 GHz), a single cycle takes about as much time as it takes a photon to travel from your monitor to your eyeball.
That's helpful. How many football fields is that?