Intel Power Consumption Then and Now

Test Setup

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CPU IIntel Core 2 Duo E685065 nm; 3000 MHz, 4 MB L2 Cache
CPU IIIntel Core 2 Extreme QX685065 nm; 3000 MHz, 8 MB L2 Cache
CPU IIIIntel Pentium D 83090 nm; 3000 MHz, 2 MB L2 Cache
CPU IVIntel Pentium 4 63090 nm; 3000 MHz, 2 MB L2 Cache
Motherboard IAsus P5E3 Deluxe, Rev: 1.03Chipset: Intel X38, BIOS 0402 (2007-09-19)
RAMCrucial BL12864BA1608.8SFB2x 1024 MB DDR3-1066 (CL 7-7-7-20 2T)
Hard Disk Drive1 Western Digital WD5000AAKS500 GB, 7,200 RPM, 16 MB cache, SATA/300
DVD-ROMSamsung SH-S183
Graphics CardGigabyte GV-RX385512HGPU: Radeon HD 3850 (670 MHz)RAM: 512 MB GDDR3 (830 MHz)
Sound CardIntegrated
Power SupplyCoolermaster RS850-EMBAATX 12V 2.2, 850 W
System Software & Drivers
OSWindows XP Professional 5.10.2600, Service Pack 2
DirectX Version9.0c (4.09.0000.0904)
Platform Drivers IntelVersion
Graphics Drivers ATICatalyst 7.11

Benchmarks and Settings

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Benchmarks and Settings
Sysmark 2007 PreviewVersion 1.02Official Run

  • hkazemi
    The 'SYSmark Performance per Watt' can be misleading when comparing the dual and quad core processors, particularly when looking at other types of loads that make better use of the additional cores. In particular, look at x264 encoding, where a quad-core processor offers nearly double performance. See the graysky's articles on TechARP for actual charts and tables:

    For a load that will use all processors, I believe that testing will show better performance per watt for a quad core compared to a dual (or even single) core because there is little or no additional overhead from the motherboard or powersupply or hard drives when adding an additional core.

    It may be easier to understand this by comparing running 2 separate PCs with dual core CPUs in them vs. running a single PC with a quad core CPU. The quad core system won't need another motherboard, power supply, fans, drives, etc. so all those items are areas of power savings.

    From the published tests above, the 2 extra cores consume 195-132=63 watts at max load and 94-77=17 watts at idle. That is in contrast to adding a 2nd system identical to the E6850 testbox which used 132 watts at max and 77 at idle.

    A simplistic scaling using a spreadsheet, and assuming that performance doubles going from dual to quad cores (reasonable for x264 encodes), shows that:

    state cores watts perf/watt perf perf/core perf ratio
    Idle 2 77 1.46 112.42 56.21 1
    Idle 4 94 2.391914894 224.84 56.21 1.638
    Avg 2 90 1.46 131.4 65.7 1
    Avg 4 112 2.346428571 262.8 65.7 1.607
    Max 2 132 1.46 192.72 96.36 1
    Max 4 195 1.976615385 385.44 96.36 1.354

    In other words, using the system power numbers given, the quad core can be 35% to 64% more efficient than using a dual core, if given an appropriate load. A look at the Sysmark benchmark scores will show you that it did not scale up very much going from dual to quad.
  • archp2008
    You said, "You cannot upgrade an existing Pentium D or Pentium 4 system with a Core 2 Duo processor, so you will have to purchase a new motherboard supporting the new processors, as well as DDR2 or DDR3 memory." My wife's P4d is on a Fox 45cmx mobo. The E6850 is listed on the support list. I was thinking of upgrading to the E6850 dual core.
  • you sure about pentium D 3.00 GHz having TDP of 215 Watt