Core Voltage
A measured average voltage of 1.319 V (with the UEFI set to just 1.195 V) shows that you can’t hold back if you want to push Haswell-E a gigahertz beyond its default peak frequency. Expect some extreme power consumption and temperature numbers.

Power Draw
The following graph shows the contrast between what we read from the voltage regulator and EPS connector, making it easy to calculate losses in the process.

At idle, power use is minimal. A 19 W result is ever-so-slightly higher than our reading at 4 GHz. But a 70 W jump under load for an additional 500 MHz tells us we can't expect much more from the Core i7-5960X on water cooling, particularly since the VR-based losses have doubled.
| Power Consumption | Average Idle | Maximum, 100% Load | Average, 100% Load |
|---|---|---|---|
| CPU 12 V In | 24 W | 280 W | 240 W |
| CPU Package | 19 W | 195 W | 192 W |
| VRM Loss | 5 W | 85 W | 48 W |
Temperatures
The temperatures at idle are still nice and low. However, those big fluctuations under load are clear indications that power delivery is becoming more erratic, and throttling is starting to become an issue. For brief periods, our Core i7-5960X cannot sustain 4.5 GHz. It jumps between 4.3 and 4.5 GHz, rather than sacrificing stability.

Here’s the time-lapse video:
| Temperature T | Idle | Maximum, 100% Load | Average, 100% Load (Heated Up) |
|---|---|---|---|
| Core | 27 °C | 87 °C | 75 °C |
| Package | 29 °C | 66 °C | |
| Water (In / Out) | 24 °C / 28 °C | 38 °C | |
| VRM | 34 °C | 67 °C |
Six Cores At 4.5 GHz
Core Voltage
Does cutting a couple of cores from the equation help bring power back under control? An average core voltage of 1.319 V is just as aggressive, surprisingly enough. Try dialing in something more conservative in the BIOS, though, and you lose stability with this particular sample.

Power Draw

At idle, there's not much difference from the six-core and 4 GHz setting. But a 50 W jump under load (60 W with losses added in) is almost as bad as what we saw from eight cores. You'll have to decide if that's worthwhile for an extra 500 MHz.
| Power Consumption | Average, Idle | Maximum, 100% Load | Average, 100% Load |
|---|---|---|---|
| CPU 12 V In | 21 W | 214 W | 175 W |
| CPU Package | 17 W | 154 W | 150 W |
| VRM Loss | 4 W | 60 W | 25 W |
Temperatures
Switching off two cores frees up enough thermal headroom to drop maximum temperatures under load by quite a bit. But that doesn't mean you can get away with a cheap air cooler, either. Liquid cooling is the way to go for its ability to quickly draw heat away from the spreader and exhaust that energy out of your chassis by blowing through a big radiator.

| Temperature T | Idle | Maximum, 100% Load | Average, 100% Load (Heated Up) |
|---|---|---|---|
| Core | 27 °C | 82 °C | 68 °C |
| Package | 29 °C | 55 °C | |
| Water (In / Out) | 24 °C / 28 °C | 36 °C | |
| VRM | 34 °C | 54 °C |
Quick escalation in our power consumption measurements push cooling into the spotlight. We're able to keep a six-core processor running well, but eight cores is pushing it. In spite of the relatively low water temperature, Intel's Core i7-5960X gets so hot that it starts throttling.
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- 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

1000$ is affordable to you ?
Though you have a point here, the guy buying such CPUs most likely will game at above 1080p .. but this would have implied using 2 GPUs at least in the test.
Bit disappointed to not see a comparison with the Xeon E5-1650v2(or 1660v2), as the 2600 is a bit overkill comparing prices. Some of us just need a workstation with ECC ram and not just a free-for-all(ie someone else is paying) Xeon 2600 fest.
1000$ is affordable to you ?
Though you have a point here, the guy buying such CPUs most likely will game at above 1080p .. but this would have implied using 2 GPUs at least in the test.
I have a hunch that we will never see anything like this in the comment sections of AMD reviews. Not sure why
Er, no. No it's not the first eight core processor. It is the first eight-core consumer or Core iN series processor though.
I also don't know of any unofficial 8-core processors either.
Intel Core i7-5960X, -5930K, And -5820K CPU Review: Haswell-E Rises : Read more
I was wondering how often you writers read the comments? Just wondering.
Gee. DDR4 save about 5 W with 4 modules. And i was worried of pwer consumption when i overclocked my FX 8350 at 4.7 GHz
Ya, the 5820K really stands out, especially in comparison to Intel's previous lowest SKU processors on X79. For the first time the x820 actually looks like a great option to go with. It's the same as a 3960X in clock speed and core count, except it's Haswell which seems to result in a 10-15% performance boost, and it's over $600 cheaper. The only drawback might be if you have a lot of high bandwidth PCIe cards, but I doubt that'll be an issue for most enthusiasts.
And omg that price:
http://www.microcenter.com/product/437203/Intel_Core_i7-5820k_33_GHz_LGA_2011_V3_Tray_Processor
... I love Microcenter.
THe improvement in multi-threaded workloads are good. It is the biggest improvement per generation we have seen since gulftown
I'm running a 780 ti and Gskill Ripjaw 1600 RAM.
How would the cost of said systems compare, assuming we could create them as equal as possible? Would the performance benefits of the 5820 justify the additional cost?
I'm still running on my old x58 i7 920, but it's starting to BSOD on CPU intensive games (although I suspect its my mobo that's the issue)...
I wanted to build a new system this year, but don't want to make the same mistake I did with the x58 and be left with something that simply can't be upgraded after a year or so. At the same time, I don't want to buy into old tech if that too won't last..
I have had a good run with my x58 mind, but am wary Intel may do what they did with my Gen 1 i7, and change something fundamental with the platform/DDR4 to mean I'll be 'stuck' with whatever I buy now...