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Pentium 4 631 Overclocked to 8 GHz
Andreas writes "There are always those who are willing to take things one step further than others. A group of guys known as OC Team Italy is one of them. They recently pushed an Intel Pentium 4 631 to over 8000MHz using an ASUS P5B with modified voltage regulation and liquid nitrogen. Overclocking is cool and all, but this extends beyond what some would perhaps call useful. Still a milestone though."
All the trouble those Italians do to cook sausage without burning it.
To save thoughs who just want to see the setup pictures
Thats just in time!
Vista is released in a couple of days, we need at least one machine up to spec.
liqbase
It's also how fast your circuits can switch, and how fast the signal can travel on the wires. The execution core of a Pentium 4 also happens to be double-pumped (i.e., it performs operations on both edges of the clock signal). Essentially, those ALUs would be switching at 16GHz ... I, personally, take this with a grain of salt.
The Raven
Indeed. Light travels just under 2 centimetres in the 16 GHz period. The Pentium 4 core is not much smaller than this... it seems like they're pushing their luck on order-of-magnitude estimates alone.
setup2
Thermometer at -192 deg.C
photo of screen at 8000.7MHz
CPU-Z verified
The extreme cooling they are doing is not just for removing the heat generated by the chip. As temperature decreases, the mobility of charge carriers increases, allowing for a faster circuit. In fact, if they were to run a supercooled chip at the nominal clock frequency, they would have hold time violations and the chip would not work. In other words, the data would propagate so quickly that it would corrupt the previous piece of data.
They just didn't want people thinking that they meant 8192MHz, I guess.
When our name is on the back of your car, we're behind you all the way!
>> Overclocking is cool and all, but [8Ghz] extends beyond what some would perhaps call useful.
:)
> Come back in a decade or two and trying saying that.
Oh, I'm sure noone would ever need more than 8gHz...
Maybe they're just trying to avoid HDD manufacturer nomenclature, where 8 GHz actually equals 7451 MHz.
Personally, I would've gone with 8,000,000,000,000,000 nHz.
Obligatory Google Calculator link
It's about performance, not MHz. Let's use SPECint as the metric. SPECint_rate scales almost perfectly with both clockspeed and core count. A P4 gets about 6.5 SPECint_rate/GHz/core, while a Core 2 gets about 11.5 SPECint_rate/GHz/core. So an 8 GHz P4 would get a score of 51.68, while a 3.4 GHz Core 2 would get 78.2.
The P4's single-core results would be substantially higher than the Core 2's single-core results, though. Interestingly, it points to what the P4 was originally designed to do: achieve high performance through high clockspeed. If process technology had met Intel's original projections, we'd have 6+ GHz P4s by now that would have been competitive with current Core 2 chips.
A deep unwavering belief is a sure sign you're missing something...
The speed of light in a vacuum (c) is the absolute maximum speed at which information can travel. It doesn't matter how much you cool the chip or what materials you make it out of, given our current understanding of physics* you can't push anything through it faster than 3*10**8 m/s. That gives you an absolute cannot-be-bettered upper limit for the distance that your signal can move in one cycle.
(* which might be wrong, but no-one's managed to prove it wrong yet)
*Light* has nothing to do with it, it's relativity and the *speed* of light in a vacuum that's important.
It's official. Most of you are morons.
Because a P4 at 8ghz benches close to an athlon at 2.
The "speed of light," by definition, is the speed at which all electric fields propagate (not just optical ones). Even though the wire is treated as an object with constant voltage on it, physically, the electric field which creates that voltage is outside of the wire. In fact, you'll find that as long as the conductance of the wire is sufficiently high, it has little effect on the speed of signal propagation. This is because at the frequencies being discussed, the wires behave more like transmission lines than the ideal, lumped-element model used in circuit analysis.
What's actually more important to the propagation speed is the permittivity and permeability of the dielectric (insulator) surrounding the wire. As it turns out, the speed of signal propagation is identically equal to the speed of light in the dielectric medium (not by coincidence, of course). I may be wrong about this, but I believe that modern processors still use undoped silicon as the interconnect dielectric medium, which means that the signal propagation speed is c/3.4.
The interconnect dielectric is usually silicon dioxide, with a relative dielectric constant of 3.9. This puts the propagation speed at about c/2.
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I like the Canadian warnings that come with photos, like impotence (4th down on this page). They're inventive. And, according to CNN, they're effective. Some of them (particularly the mouth diseases one, 8th from top) are sort of gross, though.
- Greg
Start a happiness pandemic