[geeks] Speaking of Atom and power usage..

[Jonathan C. Patschke]

On Sun, 17 Aug 2008, Geoffrey S. Mendelson wrote:

> The brilliance of the Intel Core architecture (which is an Israeli
> invention) is not that you can put multiple low performance laptop
> processors on the same die and sell it like a "real cpu", it's
> convincing people that 2 2gHz cores is as fast or faster than a 3gHz
> single desktop processor.

This is true for "Intel Core", but not so much "Intel Core 2".  "Intel
Core" as a processor family was a tweaked Pentium M that still used the
Banias microarchitecture.  "Intel Core 2" uses the "Intel Core"
microarchitecture (confused yet?) and is a different (and very impressive)
beast entirely.

Even for Intel Core, it's not so much the multiple cores that makes the
CPU so much better than the Pentium 4 it was designed to replace (for
32-bit operations, anyhow) as it was that the boneheaded design of
NetBurst made it a low hurdle to jump.  Anyone who used a Pentium M CPU
knew it was faster per-clock than any Pentium 4 before Prescott.

Beyond that, each Core 2 processing core actually is faster per-clock than
a Prescott processor for most operations--by quite a wide margin.  $ork
saw that we could not only decrease power consumption (by enough of a
measure to justify the price of upgrading), but we could get a boost in
per-job (one job per core) performance in our computing cluster by moving
from Prescott CPUs to Core 2 CPUs.  We installed roughly 400 Core 2
systems within a year of Intel shipping the first Conroe CPUs.

Switching architectures essentially took a CPU-bound problem and turned it
into a memory-bound problem.

-- 
Jonathan Patschke | "There is more to life than increasing its speed."
Elgin, TX         |                                   --Mahatma Gandhi
USA               |