Intel Core i7-5960X, -5930K And -5820K CPU Review: Haswell-E Rises

Measuring DDR4 Power Consumption

DDR4-2133: 32 GB Crucial Value RAM

Let's kick this off with DDR4's lowest data rate, 2133 MT/s, with no overclock whatsoever applied. There are no heat spreaders on our Crucial modules. Voltage is set at 1.2 V, representing significant savings compared to DDR3 and even DDR3L.Ideally, that'll translate into less heat and lower power consumption.

At idle, we measure 32 degrees Celsius at the hottest point. Not bad.

Under load, the temperatures hover around 37 degrees Celsius, which is decent as well.

DDR4-2666: 16 GB G.Skill Ripjaws

A higher clock rate and red heat spreaders are added to G.Skill's take on DDR4, but the modules are still rated for 1.2 V. How do those changes affect temperatures and power consumption?

At idle, we measure approximately 28 degrees Celsius after 20 minutes. Despite a more aggressive data rate, that's a reduction of four degrees!

Under load, the temperature we measure lands around 33 degrees. Again, that's about four degrees Celsius less.

DDR4-2800: 16 GB Corsair Vengeance

The data rate increases again, and the heat spreader is now black. Still, Corsair maintains the standard's 1.2 V setting. Unfortunately, the XMP profile for the kit's peak performance level changes the BCLK setting from 100 to 131 MHz, which directly affects the processor's frequency as well.

We measure approximately 28 degrees Celsius at idle after 20 minutes, which is the same four-degree improvement over Crucial's baseline.

The temperature remains at approximately 32 degrees Celsius under load, which represents another slight reduction (despite the highest data rate in our test).

The power consumption we measure from Corsair's DDR4-2800 kit is slightly less than the 2666 MT/s modules as well. In reality, there's basically no difference between the two kits.

DDR4 memory offers significantly-reduced power consumption, even at higher data rates. Depending on the kit you end up buying, consumption is down between 25 to 40 percent compared to DDR3.