Performance-Per-Watt & How The Raspberry Pi 2 + Pi Zero Compare To Old NetBurst CPUs

Next are some performance per Watt and power consumption data for the Raspberry Pis and an assortment of other Intel x86 CPUs -- including the old Socket 478 processors.

With x264 is the case shown on the previous page where the Raspberry Pi 2 outperforms the old Celeron...

During the x264 test, the Raspberry Pi 2 on the AC end was drawing an average of 4 Watts with a peak of 4.1 Watts, the lowest of any tested processor. The Atom Z3735F and Celeron N2820 Bay Trail systems were meanwhile at 6~9 Watts.

With the old Intel CPUs each drawing around 120 Watts during this benchmark, the Raspberry Pi 2 quad-core with its average four Watt power draw led to a power efficiency many, many times greater than these outdated Intel CPUs. However, when it came to the results stacked up against the newer Bay Trail and Broadwell hardware, these modern Intel designs were more efficient than the Raspberry Pi 2.

With Gcrypt we have a look at the Raspberry Pi Zero power consumption since it failed to build x264 for the previous test... The Raspberry Pi Zero had an average power consumption of 2.9 Watts while the Raspberry Pi 2 was at 3.1 Watts. A USB keyboard and mouse along with an HDMI display were connected to the devices during testing.

When looking at the power consumption of these two ARM devices for many different CPU tests, the Raspberry Pi Zero averaged out to 2.7 Watts with a peak of 2.9 Watts. The Raspberry Pi 2 was at 3.5 Watts with a peak of 4.1 Watts.