More Cores, but where's the Elegance?

Architecturally, the two individual die that make up Kentsfield are treated as one. This distinction matters especially when you look at power consumption of the new processor. In the event that only one of the two die is being used, the other cannot simply power down; instead it has to run at the same voltage and frequency of the other active die. Within each die, the two cores have to run at the same frequency and voltage as well, so there's not really much flexibility in operation. The end result is that while Kentsfield doesn't use too much more power than Conroe when running four CPU intensive threads simultaneously given the additional work it is doing, when only running two threads, Kentsfield is quite wasteful with its power consumption.

A more efficient solution would be to allow each core to operate at its own frequency, and an even better implementation would require independent power planes per core - allowing for different voltages depending on load. As simple as these two options are to write, they are unfortunately far more difficult to implement. AMD has already announced that its Barcelona quad-core CPUs will support independent clock speeds per core, but not independent voltages.

AMD's Barcelona core, due out in Q2 '07, will have support for independent clocks per core but all sharing the same voltage

Index Using a Quad Core System
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  • JJWV - Tuesday, January 23, 2007 - link

    I bought a QX6700 for crunching at numbers. The reasoning was simple twice the power, only one MB, disk, PSU, case...

    The result is disappointing, the maximum throughput I get is not twice an E6700, it is just a little more than one an half : 1,6 to be precise. The bottleneck is definitely the memory. The Northbridge cannot communicate fast enough with the memory. 5I came to this conclusion by varying multiplier, FSB...) Perhaps it would be worthwhile with the faster memory available 9200, but I am afraid even that kind of memory is to slow. The Quadcore is where Intel went over the edge with their memory architecture.
  • Kougar - Tuesday, November 14, 2006 - link

    Any ideas on the Apache benchmarks I am seeing with a QX6700? They are appalling at best, with a QX6700 performing on par to a E6400!! A little of the same problem seems to have shown up in Office Productivity benchmarks. Any thoughts on this?
  • in1405 - Monday, November 6, 2006 - link

    <<<No article looking at a new processor release would be complete without benchmarks. However, let us preface the benchmark section by stating that the benchmarks don't tell the whole story. There are numerous benchmarks and tasks that you can run that will actually show quad core processors in a better light. A lot of people will never use the applications related to these benchmarks, so in one sense we could say that most people should already know whether or not they need quad core processing.>>>

    Some interesting comments here on the relevance of Benchmarks .. This looks interesting as this point of view never came up while the AMD CPUs were being glorified a few months back in this same site!! Wonder where the sudden wisdom comes from.
  • LTC8K6 - Sunday, November 5, 2006 - link

    Why not compare dual to quad by trying to run things in the background while you do something in the foreground? Encode something and play Oblivion, for example. Would we finally be able to do anything like that with quad cores? Are we able to get good framerates in such a situation yet?
  • Webgod - Thursday, November 2, 2006 - link

    How about running">DriverHeaven.Net's Photoshop CS2 benchmark? I think one of your standard magazine benchmarks has Photoshop 7, but the DH benchmark is newer and it's somewhat popular. Anybody can download a demo from Adobe, and run the benchmark on their own PC.
  • coldpower27 - Thursday, November 2, 2006 - link

    Check Intel's current price list here:">
  • JarredWalton - Thursday, November 2, 2006 - link

    Actually just the 820 and 914 - 805 didn't get a price cut this month. But I fixed the other two, thanks. :)
  • coldpower27 - Thursday, November 2, 2006 - link

    oh yeah my bad, didn't mean to add the 805 in there.

    by the way, check your email please.
  • OddTSi - Thursday, November 2, 2006 - link

    On page 7 you say "Apple's OS X and its applications have also been well threaded for quite some time..." yet the only two Apple apps in the test (Quicktime and iTunes) didn't scale AT ALL from 2 to 4 cores. I'm not trying to bash Apple here I'm just trying to point out that the facts don't seem to support your assertion. If Apple's media rendering apps - which are some of the easiest to multithread - don't scale well I doubt that the rest of their apps do.
  • mino - Thursday, November 2, 2006 - link

    Maybe cause there is a catch?
    You see, WinXP is not very OSX like, not to mention its apps ;)

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