Core Voltage
Overclocked to 4 GHz, our Core i7-5960X's core voltage is now 1.110 V. This time around we're optimizing it manually to minimize power consumption and temperature.

Power Draw
The following chart contrasts the VRM's measurement with our reading at the EPS connector, in addition to power losses due to the voltage regulation circuit.

A reading of 18 W at idle is identical to what we just saw at 3.5 GHz. However, the increase to 124 W under load shows that the eight-core configuration running at 4 GHz is starting to pull quite a bit more power from the wall.
Still, these figures are within reason considering the performance you get in return.
| Power Consumption | Average Idle | Maximum, 100% Load | Average, 100% Load |
|---|---|---|---|
| CPU 12 V In | 22 W | 165 W | 146 W |
| CPU Package | 18 W | 128 W | 124 W |
| VRM Loss | 4 W | 43 W | 23 W |
Temperatures
The temperatures at idle don't increase. And as clock rate goes up, the difference between each core's minimum and maximum temperature becomes more pronounced, too.

It’s time for a look at the time-lapse video.
| Temperature T | Idle | Maximum, 100% Load | Average, 100% Load (Heated Up) |
|---|---|---|---|
| Core | 27 °C | 57 °C | 48 °C |
| Package | 29 °C | 48 °C | |
| Water (In / Out) | 24 °C / 27 °C | 32 °C | |
| VRM | 34 °C | 47 °C |
Six Cores At 4 GHz
Again, we want to try the same thing using six cores to estimate how the Core i7-5930K or -3820K might behave.
Core Voltage
Registering 1.100 V, there’s barely any difference in CPU core voltage between the six- and eight-core models.

Power Draw

Disabling two cores yields a reduction in power consumption to 17 W at idle (21 W if you count the VR) and 101 W under load. That's notably less than the eight-core configuration.
| Power Consumption | Average, Idle | Maximum, 100% Load | Average, 100% Load |
|---|---|---|---|
| CPU 12 V In | 21 W | 137 W | 115 W |
| CPU Package | 17 W | 105 W | 101 W |
| VRM Loss | 4 W | 32 W | 14 W |
Temperatures
Here are the temperatures under load:

| Temperature T | Idle | Maximum, 100% Load | Average, 100% Load (Heated Up) |
|---|---|---|---|
| Core | 27 °C | 53 °C | 46 °C |
| Package | 28 °C | 44 °C | |
| Water (In / Out) | 24 °C / 27 °C | 31 °C | |
| VRM | 34 °C | 45 °C |
Our eight- and six-core setups increase about 20 W when we overclock to 4 GHz. It's easy to see that we're operating Haswell-E above its sweet spot. Nevertheless, you should be able to hit a stable overclock at comparable performance levels using a big heat sink. Just be sure you have a high-end cooler and a chassis with good airflow.
- Three New CPUs For Enthusiasts
- X99, LGA 2011-3 and DDR4: Get Ready For A Big Upgrade
- How We Tested Core i7-5960X, -5930K, And -5820K
- Synthetic Benchmarks
- Real-World Benchmarks
- Battlefield 4, Grid 2, And Metro: Last Light
- Star Swarm, Thief, Tomb Raider, And WoW
- Power, In Depth: Stock Clock Rates
- Power, In Depth: Eight and Six Cores at 3.5 GHz
- Power, In Depth: Eight and Six Cores at 4 GHz
- Power, In Depth: Eight and Six Cores at 4.5 GHz
- Power, In Depth: CPU Health at 4.8 GHz
- Measuring DDR4 Power Consumption
- Power Consumption Through Our Benchmark Suite
- Intel Keeps Enthusiasts On Its Most Modern Design With Haswell-E

Personally, the 3DS and After Effects benchmarks were of most interest, since they are what I spend most of the CPU time on. (3DS in particular, right now I'm logging dozens of CPU hours a day on 3DS alone). It's pretty clear that unless the platform costs of Haswell-E are much higher than IB-E, going with the old won't make sense. The 5930k beats the 4960X. which is at least 50% more expensive.
I've been waiting forever for an upgrade to my i7 930 based workstation, and I didn't feel like jumping on an IB-E a couple months before a brand-new HEDT platform is released.
I had hoped Haswell-E would be a bit more impressive, but OTOH, investing in a DDR4 platform now might be a good idea, given my workstations typically have 3-4 years in them. At the very least, a drop-in upgrade to Broadwell-E would be nice to have as an option.
Now to see how big a pounding I'll take in Denmark for X99/DDR4/Haswell-E...
Therefore anybody who's going to load up on GPUs enough to worry about PCI-E lanes will have sufficient money to drop in a 5960X on principle. Anybody who's adopting X99 for productivity purposes will not skimp on core count and also go 5960X, especially considering they're likely to go at least 32GB RAM and therefore shelling out a lot of money. Those producing on CUDA cards may not even go X99 at all because 1150 Haswell has more than enough power to run the software. Folders and CUDA Miners similarly will want all GPUs running at full tilt so will likely invest in the 5960X to get all the PCI-E lanes.
So really, the only "smart choice" is 5960X or don't go X99 at all.