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Intel Launches Power-Efficient Penryn Processors
Bergkamp10 writes "Over the weekend Intel launched its long-awaited new 'Penryn' line of power-efficient microprocessors, designed to deliver better graphics and application performance as well as virtualization capabilities.
The processors are the first to use high-k metal-gate transistors, which makes them faster and less leaky compared with earlier processors that have silicon gates. The processor is lead free and by next year Intel is planning to produce chips that are halogen free, making them more environmentally friendly.
Penryn processors jump to higher clock rates and feature cache and design improvements that boost the processors' performance compared with earlier 65-nm processors, which should attract the interest of business workstation users and gamers looking for improved system and media performance."
While Penryn is a small increase in performance, it is not a big change in the architecture. Instead of upgrading to Penryn, customers can expect Nehalem, the next major revision in the Intel architecture, was responsible for the release in 2008.
At the Intel Developer Forum in San Francisco in September Intel showed, and said it would be a better yield per watt and better system performance through its Quick Path Interconnect system architecture. Nehalem chips will also provide a memory controller integrated and improved communication between system components.
It was, when the Pentium Pro was introduced circa 1997. The instruction set the programmer "sees" is not the instruction set that the chip actually runs.
The energy required to switch a capacitor from zero to Vdd volts is 1/2*C*Vdd^2.
Smaller logic sizes can operate faster because the physical gate area of the transistor is that much smaller, so there's less capacitance loading down the piece of logic before it (proportional to the square of the scaling, of course). However, it also tends to be the case that the operating voltages scale down too (because they adjust the semiconductor doping and the gate oxide thickness to match), so you get an even better effect on energy required. Thus, scaling helps both with speed and operating power.
The problem they're running into now is that at these smaller sizes, the off-state leakage currents are getting to be of the same magnitude as the actual switching (operating logic) currents! This happens because of the reduced threshold voltage when they scale down, so the transistor isn't as "off" as it used to be.
That's why Intel has to work extra hard to get the power consumption down as the sizes scale down.
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NerdKits: electronics kits for the digital generation.
Smaller size means signals can propagate around the chip faster. It also means you need less signal-fixing/synchronization hardware, since it is simpler to get a signal synced up at a given clock rate. Smaller size generally means less power dissipated. Smaller feature sizes means the CPU is physically smaller (generally), so more CPUs fit on a silicon wafer. For each wafer they produce (a high but relatively fixed cost vs the number of CPUs on the wafer) they get more CPUs out (= cheaper). If a CPU is bad, that is a smaller percent of the wafer that was "wasted" on that CPU.
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Actually, one of the reasons that Apple jumped off of the PowerPC platform was BECAUSE of their power inefficiency. The G5 processors were incredibly power hungry, enough so that they could never get one cool enough to run in a laptop and actually offered the Mac Pro line with liquid cooling. Compare that to the new quad-core and eight-core mac pro's and dual core laptops that run very effectively with very minimal air cooling.
These days:
One of the real problems with x86-32 was the low number of registers, which resulted in many stack spills. x86-64 added 8 more general purpose registers, and the situation is much better (that's why most people see a 10-20% speedup when migrating to x86-64 - more registers). Sure, it'd be better if we had 32 registers ... but again, with 16 registers life is decent.
The Raven