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."

direct link to photos of setup

[Bananatree3]

To save thoughs who just want to see the setup pictures [xtremesystems.org]

The problem with high clock is not just heat ...

[vlad_petric]

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.

Re:Just in Time!

[Anonymous Coward]

I'm running Vista on my 1.8 GHz dual core AMD Turion 64 Acer Ferrari 1000 with 1.75 GB of RAM and a 256 MB ATI Radeon right now. Vista and Office 2007 are very responsive and the UI is very good.

photo mirror

[Bananatree3]

setup1 [imageshack.us]

setup2 [imageshack.us]

Thermometer at -192 deg.C [imageshack.us]

photo of screen at 8000.7MHz [imageshack.us]

CPU-Z verified [imageshack.us]

Re:The problem with high clock is not just heat ..

[ettlz]

f = 16 GHz = 16 × 10^9 1/s gives a period t = 1/f = 0.0625 × 10^(–9) s. Distance x = ct = 3.00 × 10^8 m/s × 0.0625 × 10^(–9) s = 0.019 m. But yes, a THz chip would be seriously up-fucked.

Re:The problem with high clock is not just heat ..

[product byproduct]

Obligatory Google Calculator link [google.com]

Re:8GHZ and still not as fast

[be-fan]

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.

Re:The problem with high clock is not just heat ..

[Ford Prefect]

How fast electrical signals travel through the wires is depending on the material the wires are made of. Light has nothing to do with it.

While light itself may not have anything to do with it, the speed of light c most definitely has. It's the upper speed limit for, well, everything. Including propagation of signals.

Re:The problem with high clock is not just heat ..

[Tim C]

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.

Re:Why not 8 GHz?

[evilbessie]

They have infact already designed and approved (IEC and IEEE) them, it's just that no one uses them really, so they look out of place. Basically the words change to Kibi, Mebi, Gibi, Tebi, Exbi, Zebi and Yobi; http://en.wikipedia.org/wiki/Binary_prefix [wikipedia.org] to signify increases of 2^10 rather than the decimal 10^3. You also add an i so it's GiB or Mib.

But all I thought when I read the story was of the reasoning of turning Mars into a giant space ship, whilst wiping out your own civilisation. "Because it's cool".

Re:The problem with high clock is not just heat ..

[Anonymous Coward]

> Isn't that the supposed upper speed limit for objects? Electric signals in a wire can go faster than the electrons are moving, or so I think (electrons "hopping" to atoms, as such not travelling the width of the atom, etcetc... might be terribly wrong here). If that is true, electrical signals can in theory travel faster than light.

Despite all this, in theory, electrical signals do not travel faster than light.

> I once heard of a experiment at CERN (I think) where they managed to push a particle beyond the speed of light in that enviroment, creating a light-wave very much akin to an ultrasonic boom. Don't know the details.

Look up cherenkov radiation. The particle in question might have gone faster than c in that medium, but it didn't manage to go faster than the speed of light in vacuum.

Re:The problem with high clock is not just heat ..

[Manchot]

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.

Stop comparing GHz !!!

[DrYak]

Pentium 4 is based on a Netburst architecture.
Core 2 duo is derived from a Pentium D architecture (which was itself carried from Pentium3 / Pentium2 / Pentium Pro).

They're completly different animals and definitly not doing the same stuf during 1 cycle.

C2D 6.8Ghz can't be compared to the 8Ghz overclock.

That's also why Intel switched from advertising MHz/GHz to advertising number of cores. Otherwise, newer and faster would have been considered by joe 6-pck because he's been trained to look for the "GHz" and Core Duo happens to have lower clock for similar performance as pentium 4s.

Whether this new "old GHz = new Num_of_Cores" marketing craze actually means something or is just hype (as opposed to trying to add task-specific coprocessors like IBM's Cell and AMD's Fusion etc.) is left to the speculation of the reader.

Re:The problem with high clock is not just heat ..

[ChrisMaple]

The interconnect dielectric is usually silicon dioxide, with a relative dielectric constant of 3.9. This puts the propagation speed at about c/2.

Re:Sheesh...

[gbulmash]

Sous-vide, IIRC, requires a consistent, controlled temperature. You'd definitely need to write a system monitor that keeps the processor at a specific load (not above, not below) so you could maintain that perfect cooking temperature.

- Greg

Re:"Smoking kills"

[gbulmash]

I like the Canadian warnings [smoke-free.ca] that come with photos, like impotence (4th down on this page [smoke-free.ca]). They're inventive. And, according to CNN [cnn.com], they're effective. Some of them (particularly the mouth diseases one, 8th from top) are sort of gross, though.

- Greg

whoever modded this flambait

[Anonymous Coward]

obviously hasn't seen the producers

Urg - link mangled

[dangitman]

I think the tobacco industry destroyed my link, those sneaky bastards.

Check out these Australian cigarette packets [wikipedia.org].

Re:The problem with high clock is not just heat ..

[fatboy]

How fast electrical signals travel through the wires is depending on the material the wires are made of.

Actually, the velocity of propagation [wikipedia.org] equals the reciprocal of the square root of the dielectric constant of the material through which that signal passes.

Re:The problem with high clock is not just heat ..

[NixieBunny]

I know you're being silly, but I've measured both. I found that electricity on a printed circuit board (I know, not technically a wire) is 2 nanoseconds/foot, which is half as fast as light in air. Most coaxial cables' velocity factor is rated at about 70% of the speed of light.

Measuring the speed of light to 1% accuracy with junk-drawer parts and Ebay bargain istruments is not trivial, but it can be done.