Intel Scraps Plan For 4 Ghz P4 Chip

bizpile writes "It was reported earlier that Intel would be delaying the release of their 4Ghz Pentium 4 chips, but it now appears that they will be cancelling them altogether. The announcement came Thursday and Intel says they are going to rely on approaches besides faster clock speed to improve the performance of chips. Engineers are working to add additional cores to a single chip and improving the efficiency in how the chips interact with the rest of the system. Intel spokesman Chuck Mulloy said, "Those are the sort of things where you get more capability out of a processor by designing specific silicon solutions as opposed to just keep turning the clock faster." In the meantime, Intel is planning on releasing a 3.8 Ghz chip with 2mb of cache."

Comments

Re:So much for Moore's Law

[kamikazichaser]

Actually, Moore says that chip complexity will double along with relative performance, not clock speed. If Intel goes ahead with dual cores, and maybe quad cores later, then Moore's law is safe...for now

Re:Bound to happen sooner or later

[Sebastopol]

Common misconception. Electrons don't move at the speed of light. In fact, electrons aren't the primary charge carrier in half the transistors in the chip. Holes are (P vs. N).

Charge carriers propagate at about the speed of molasses. Go read this website, it is great:

http://amasci.com/miscon/eleca.html#light

Here's an excerpt --

THE "ELECTRICITY" INSIDE OF WIRES MOVES AT THE SPEED OF LIGHT? Wrong.
In metals, electric current is a flow of electrons. Many books claim that these electrons flow at the speed of light. This is incorrect. Electrons actually flow quite slowly, at speeds on the order of centimeters per minute. And in AC circuits the electrons don't really flow at all, instead they sit in place and vibrate. It's the energy in the circuit which flows fast, not the electrons. Metals are always full of movable electrons, and when the electrons at one point in the circuit are pumped, electrons in the entire loop of the circuit are forced to flow, and energy spreads almost instantly throughout the entire circuit. This happens even though the electrons move very slowly.

Re:Bound to happen sooner or later

[drmerope]

You're also off the mark. It is almost certain that there is no electrical pathway that spans the chip without hitting some logic. The number in 90nm (for best performance) is about 12000\lambda (\lambda = 90nm). Often signals propogate much smaller distances in a cycle. I assure you in one cycle no one is making a signal traverse the entire core. Modern CPUs are highly pipelined which is essentially to say that in one clock cycle data is transfered and processed within a very small section of the chip before being passed on to the next stage. This then frees the stage for the next bit of data. see http://en.wikipedia.org/wiki/Pipelining As a side consequence, what you mention is not the limiting the factor. Signals simply do not need to propogate across the chip in one cycle. What has really happened is the drive current available from each transistor has gotten smaller as the transistor itself has shrunk. The wiring capacitance has remained the same and begun to predominate over the gate capacitence. Thus, making the transistors smaller does not make the circuit faster as it once did. Also, as someone else pointed out, the mobility of electrons in semiconductors is no where near the numbers you quote. Electronics simply don't work the way you claim.

Not just MHz

[mwdmeyer]

Remember intel has done other things to increase speed other than just MHz increase. Such as: 1) Increase Front Side Bus (in the p4's case 400 -> 533 and now 800MHz) 2) Increase Cache (256 -> 512 -> 1024 -> 2048kb) 3) SSE 1, 2 and 3 4) HyperThreading