Power consumption

When overclocking:

During the overclocking we experienced some difficulties keeping the system stable. When finally even the phase change cooling had a hard time running the setup, we took a closer look.
While stressing the 4 cores / 8 threads using the phase change, we saw temperatures going up from -46° C to almost 0° C. The mounting wasn't the best, neither was the insulation, but this was the proof that we had a good contact with the core. Did the Mach 2 pass out on us ?

First a look at the setup used while overclocking:

Test Setup Core i7 overclocking
CPU	Intel Core i7 Extreme 965
Cooling	Intel Boxed cooler Nventiv Mach 2 (R507 modded)
Mainboard	Intel Extreme Motherboard DX58SO
Video card	Nvidia Geforce 7100 GS
Memory	3 * 1024 Mb DDR3 PC12800 OCZ
Other	Zalman 1000 watt PSU WDC 320 Gb Sata

And now the power usage; but some remarks.

The 1.55 Vcore test were done using Phase change, thus lower consumption and lower power usage as confirmed by Intel here.

Not the entire system was stressed, just the processor (and indirectly also mainboard) using the CPU test in Sisoft Sandra.

C1E was disabled and so was speedstep.


Graph with power consumption while overclocking.

We also did a very last minute test with the Intel QX9770, paired with i-ram and an Nvidia 280 GTX videocard. By just stressing the processor we measured a 221 watt power consumption. Idle this was 175 watt. So stressing the cpu gives us an extra 56 watt in default configuration. While this was over 70 watt for the Core i7. (177-103)

At 1.55 Vcore the entire setup is using almost as much as 450 watt. Considering the low end card used, and which was kept idle, we have a 290 watt raise in consumption. Now we understand why the phase change had problems keeping this chip more or less stable.

Total consumption was:

Idle power of a default chip, difficult to measure but system was running at only 103 watt.

Extra wattage just by adding more Vcore (from 103 to 159) gives already 55 watt in idle state extra.

Stressing the setup adds a whopping 290 watt.

The chip is using 345 watt, plus what it uses when it's idle, minus the correction of the mainboard and memory when stressing the cpu, still gives an awful lot off heat that is dissipated.

A default configuration:

Keep in mind that the previous numbers were in extreme circumstances. We also measured the system and compared it to an older, 45 nm based configuration.
In this scenario the entire system was loaded using Futuremark 3d mark 2006. And we also had another configuration:

Normal consumption comparison
CPU	Intel Core i7 Extreme 965 Intel Core i7 920 Intel Core 2 Duo E8600
Cooling	Intel Boxed cooler
Mainboard	Asus P6T Deluxe Asus Maximus II Formula
Video card	AMD Radeon HD 4870X2
Memory	3 * 1024 Mb DDR3 PC12800 OCZ 2 * 2048 Mb DDR2 PC8500 OCZ
Other	Zalman 1000 watt PSU WDC 320 Gb Sata

In the following graph you see that the complete Core 2 Duo E8600 setup uses about as much power as the New Core i7 configurations. So Intel didn't do any better ?
They even did a lot better, added 2 more cores and kept consumption levels as they were before. More for less, or about the same in this case.


Power consumption of various configurations

Most aspects of this new architecture have been discussed, so it's time to wrap things up.