Power Consumption

For all of the performance tests, we disable all power saving technology in order to give us a consistent set of results, and also best-case performance numbers - even though technologies such as Intel's SpeedStep might only take microseconds to kick in, that can make a difference in some tests.

For Core i7 CPUs we disable SpeedStep, C1E support, Intel C-State technology and Turbo Boost (despite this being a default performance enhancement technology, it can make benchmarks unreliable). We would normally disable HPET too, but the Asus P6T Deluxe doesn't offer this. For Socket AM3 CPUs, we disable Cool'n'Quiet, C1E support and HPET.

However, for the power consumption tests we re-enable everything but Intel's Turbo Boost in order to get a real-world power draw.

Idle Power Consumption

For this test, we leave the PC doing nothing but displaying the Windows Vista desktop (with Aero enabled) for a few minutes and record the wattage drawn from the wall via a power meter.


The power consumption has been considerably reduced with the latest C3 965 Black Edition, saving a significant 27W at stock speed when idle, and even 23W when overclocked even faster than the C2. This even puts the whole system at a lower power than the Core i7-920, although the i5-750 still trumps it by nearly 30W.

Full Load Power Consumption

For this test, we run the small FFT test of Prime95 (v25.9) across all available processing threads and record the wattage drawn from the wall via a power meter.


Full load performance is actually best of the bunch when overclocked - it's over 27 per cent lower power than the Core i7-920 and 8W lower than the i5-750 too, however, performance efficiency will still be in favour of the i5. At stock speeds it's still power hungry compared to the competition, but when we look at its older C2 brother, it is significantly better: 13W at stock and a whopping 45W when overclocked.

Conclusion

With some obvious and noteworthy improvements to the C3 revision of the Phenom II X4 965 Black Edition, it's now become a slightly more attractive alternative to the strong Intel competition.

The vastly improved memory controller overclocking potential and much lower power use has clear benefits to performance and not having a system that sounds like a hurricane. Despite the fact there's only slightly more MHz available without very heavy cooling (although extreme overclocker will no doubt be happy), it does take another small chink out of the mighty Intel armour.

Intel's two popular CPUs still take a commanding lead however, but with the Core i7-920 hoarding £200 of your cash, plus cost of more expensive X58 motherboard, it's in a bracket above what the Phenom II X4 965 Black Edition is aimed at. It's the Core i5-750 that still keeps AMD's premium CPU down though.

Despite the fact Intel's processor is £5-10 more, both have appreciably similar motherboard cost and can use the same dual channel DDR3. So, for the cost of lunch, the performance difference is still considerable - especially when overclocked. The only area where we found AMD wins is under overclocked load surprisingly enough: 293W versus 285W at the wall, however idle power draw and efficiency through getting the job done faster is largely more in favour of Intel.

AMD's improved alternative is now a better and even quite a good alternative, but we're still going to recommend the Core i5-750 and P55 platform if your build budget falls in this range.

• Performance
• x
• x
• x
• x
• x
• x
• x
• -
• -
• -
• 7/10

• Value
• x
• x
• x
• x
• x
• x
• x
• -
• -
• -
• 7/10

• Overall
• x
• x
• x
• x
• x
• x
• x
• -
• -
• -
• 7/10

Score Guide