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Overclocking Intel's Core i7 920

Power Consumption

When we test power consumption, we consider it as a whole platform so whether the CPU includes a memory controller or it's separate on the northbridge doesn't make a difference to what we measure at the wall and how much electricity is paid for. The Core i7s are built on a 45nm process which should be low power, and with all the Power Saving gizmos from the CPU, memory and QPI etc turned up to eleven we set about seeing whether this meaty platform could go to sleep and stay quiet.

While it's difficult to compare the motherboards in an apples to apples scenario, none of the motherboards used feature specific power regulation for the CPU phases and all of them are performance parts from DFI, Intel and Asus.

Hmm well, the idle power consumption is only a 50W (or 50 percent) increase - but this should be in line with Q6600's overclocked and overvolted. Load values are, hmm, "high", but remember that we're overvolting and overclocking the four cores, the uncore and the memory quite a way. That increment means this CPU subsystem has a 179W increase in power output - so predominantly you'll need a cooling solution to tame this. We've found both the Noctua NH-U12P and Thermalright Ultra 120 eXtreme 1366-RT still handle it very well indeed - is a £35 CPU cooler investment worth the huge saving in CPU cost? Absolutely.

Idle Power Consumption

Power at wall socket. BIOS Defaults, all onboard hardware enabled. Windows Desktop Idle

  • Core i7 940 (4x2.93GHz, 45nm)
  • Core i7 920 (4x2.66GHz, 45nm)
  • Core i7 965 (4x3.2GHz, 45nm)
  • Core 2 Quad Q9450 (4x2.66GHz, 45nm C1, DDR2)
  • Core 2 Duo E8500 (2x3.16GHz, 45nm C0, DDR2)
  • Core 2 Quad Q9650 (4x3.0GHz, 45nm C0, DDR2)
  • Core 2 Extreme QX9770 (4x3.2GHz, 45nm C0, DDR2)
  • Core 2 Quad Q9550 (4x2.83GHz, 45nm C1, DDR2)
  • Core 2 Quad Q9650 (4x3.0GHz, 45nm C0, DDR3)
  • Core 2 Duo E8500 (2x3.16GHz, 45nm C0, DDR3)
  • Core 2 Quad Q9450 (4x2.66GHz, 45nm C1, DDR3)
  • Core 2 Quad Q9550 (4x2.83GHz, 45nm C1 DDR3)
  • Core 2 Extreme QX9770 (4x3.2GHz, 45nm C0, DDR3)
  • Core 2 Quad Q6700 (4x2.66GHz, 65nm G0, DDR2)
  • Core 2 Quad Q6700 (4x2.66GHz, 65nm G0, DDR3)
  • AMD Phenom X4 9750 (4x2.4GHz, 65nm B3)
  • AMD Phenom X4 9950 BE (4x2.6GHz, 65nm B3)
  • AMD Phenom X4 9850 BE (4x2.5GHz, 65nm B3)
  • Core i7 920 OC (4x4GHz, 1,600MHz DDR3, 3.6GHz QPI)
    • 103.0
    • 103.0
    • 104.0
    • 107.0
    • 107.0
    • 107.0
    • 107.0
    • 108.0
    • 113.0
    • 113.0
    • 113.0
    • 114.0
    • 115.0
    • 130.0
    • 133.0
    • 137.0
    • 137.0
    • 137.0
    • 149.0
0
25
50
75
100
125
150
Watts (lower is better) - Average Reading
  • Idle

Load Power Consumption

Power at wall socket. BIOS Defaults, all onboard hardware enabled. Prime95 Load

  • Core 2 Duo E8500 (2x3.16GHz, 45nm C0, DDR2)
  • Core 2 Duo E8500 (2x3.16GHz, 45nm C0, DDR3)
  • Core 2 Quad Q9450 (4x2.66GHz, 45nm C1, DDR2)
  • Core 2 Quad Q9450 (4x2.66GHz, 45nm C1, DDR3)
  • Core 2 Quad Q9650 (4x3.0GHz, 45nm C0, DDR3)
  • Core 2 Quad Q9550 (4x2.83GHz, 45nm C1, DDR2)
  • Core 2 Quad Q9550 (4x2.83GHz, 45nm C1, DDR3)
  • Core 2 Quad Q9650 (4x3.0GHz, 45nm C0, DDR2)
  • Core 2 Extreme QX9770 (4x3.2GHz, 45nm C0, DDR2)
  • Core 2 Extreme QX9770 (4x3.2GHz, 45nm C0, DDR3)
  • Core i7 920 (4x2.66GHz, 45nm)
  • Core i7 940 (4x2.93GHz, 45nm)
  • Core 2 Quad Q6700 (4x2.66GHz, 65nm G0, DDR3)
  • Core 2 Quad Q6700 (4x2.66GHz, 65nm G0, DDR2)
  • AMD Phenom X4 9750 (4x2.4GHz, 65nm B3)
  • Core i7 965 (4x3.2GHz, 45nm)
  • AMD Phenom X4 9950 BE (4x2.6GHz, 65nm B3)
  • AMD Phenom X4 9850 BE (4x2.5GHz, 65nm B3)
  • Core i7 920 OC (4x4GHz, 1,600MHz DDR3, 3.6GHz QPI)
    • 142.0
    • 152.0
    • 175.0
    • 177.0
    • 178.0
    • 179.0
    • 179.0
    • 180.0
    • 184.0
    • 186.0
    • 196.0
    • 211.0
    • 215.0
    • 240.0
    • 243.0
    • 247.0
    • 254.0
    • 256.0
    • 375.0
0
100
200
300
400
Watts (lower is better) - Average Reading
  • Load

Omnomnomnomnom. The overclocked Core i7 920 definitely likes to eat power!