Broadwell-E: Intel Core i7-6950X, 6900K, 6850K & 6800K Review

Test Setup & Overclocking

Test System and Processors

Core i7-6950X
Core i7-6900KCore i7-6850K
Core i7-6800K

Motherboard & Memory

We’re using MSI's X99A Gaming Pro Carbon as the basis for our benchmarks and overclocking attempts. As mentioned previously, this is a refreshed X99-based platform that modernizes Intel's aging chipset a bit with USB 3.1 Gen 2 support, Type-C port connectivity and a U.2 connector for high-end storage.

If you're new to building PCs, MSI's Game Boost is an interesting one-button overclocking feature. Of course, experienced power users are going to tweak their settings manually, but it's still nice to have options.

One of the most important components of a stable overclock is the right memory. We’re using four 8GB modules of G.Skill Trident Z DDR4-3200 for our X99, X79 and Z170 platforms. This should assure our Broadwell-E overclocks aren't limited by memory.

The only difference between our performance benchmark system and the one for overclocking/power consumption testing is cooling. We don't want to risk hitting a thermal ceiling, so the platform we're tuning employs an open-loop water cooling setup that can get rid of as much as 500W of waste heat. These CPUs shouldn't come close to that number, but you never know...

Benchmarks

Ashes of the Singularity2560x1440, Point Lights: High, Glare, High, Terrain Detail Object Level: High, Shading Samples: 16, Terrain Detail Shading Samples: 32, Shadow Quality: High
Bioshock Infinite2560x1440, Ultra quality preset, Light Shafts: On, Ambient Occlusion: Ultra, Object Level of Detail: Ultra
F1 20152560x1440, 4x SSAO, 16x anisotropic filtering, Post-processing options enabled, Shadows enabled, Smoke shadows enabled, Vehicle reflections enabled, Weather effects enabled, Ground cover enabled.
3DMarkFire Strike version 1.1
7-ZipVersion 16.02, LZMA2 method, Ultra compression, 4.52GB workload, mixed file types
BlenderVersion 2.75a, Cycles engine, BMW benchmark
CinebenchVersion R15, Single- and multi-threaded CPU benchmark
HandBrakeVersion 0.10.2, x264, Constant quality: 20, variable bit-rate
LAMEVersion 3.99, .wav to .mp3 conversion, 160 Kb/s fixed bitrate
PCMark 8Version 2.7.613, Hardware acceleration enabled, Adobe Creative Cloud and Microsoft Office suites

Overclocking & Stability

Our overclocking methodology includes increasing each CPU's clock rate until we discover the maximum for a fully utilized processor and even faster Turbo Boost settings for each core. We also adjust voltages as-necessary to achieve a balance between stability and waste heat, since this directly affects cooling.

With a configuration that boots successfully, we run different load scenarios to verify stability. After completing Aida64’s integrated stress test (CPU, FPU, cache), the system is faced with workloads created by a Creo 3.0 SPECapc run, 4K video compression using the Adobe CC Media Encoder, a Witcher 3 sequence, Prime95 and AVX.

A clock rate configuration is only considered successful if those workloads finish without any errors and within reasonable voltages. Before we get to the results, here’s a table with our test system’s technical specifications:

Power Consumption Test Setup

Test Method
Contact-free DC Measurement at External Auxiliary Power Supply Cable
Direct Voltage Measurement at Power Supply
Real-Time Infrared Monitoring and Recording

Test Equipment
2 x Rohde & Schwarz HMO 3054, 500MHz Digital Multi-Channel Oscilloscope with Storage Function
4 x Rohde & Schwarz HZO50 Current Probe (1mA - 30A, 100kHz, DC)
4 x Rohde & Schwarz HZ355 (10:1 Probes, 500MHz)
1 x Rohde & Schwarz HMC 8012 Digital Multimeter with Storage Function
1 x Optris PI640 80Hz Infrared Camera + PI Connect
Water Cooling
Pump: Alphacool VPP655 (Undervolted, 50 percent)
CPU Cooler: Lian Li
Reservoir: Phobya
Radiator: Alphacool, 24cm (6cm thickness)
Fan: 2x 12cm Noiseblocker eLoop, PWM controlled (up to 1500 RPM)

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126 comments
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  • jt AJ
    was expecting a bit more info and review usage of turbo 3.0. also looks like most of broadwell E chip is junk.. except that one 6850k chip you received probably lucky 1.25v for 4.4v would be good thats only because its broadwell. got one here for 4.8ghz at just 1.22v.
  • Nuckles_56
    Chris, how likely is it that a noctua NH-D15 would be able to cool these heat producing monsters if your h100i struggled and failed with the i7-6800k @4.4GHz.

    But a truly excellent review, even if it does show that there is little reason to go to broadwell-E over Haswell-E
  • elho_cid
    I'd love to step up to the realm of higher core count, but given the results of Adobe SW when scaling to many threads, meas it is not really useful right now. :/
    That's a pity, because the most time I spend staring at a progress bar is when I'm using Adobe products. I don't really need more power to "background tasks" like zipping or lame encoding.
  • AdmiralDonut
    Standard SLI is not limited on the new NVIDIA cards. The only thing that's limited is the new High Bandwidth SLI. Normal 3 and 4-way SLI can be enabled easily by simply asking NVIDIA for an unlock code, something any half way serious enthusiast will most certainly do. Here's some more info on this matter:

    https://www.youtube.com/watch?v=2wBDt9tN5-c
  • bit_user
    I don't really see the point of having a $1700 non-Xeon SKU. Of the few people who can afford it, even less would bother/dare to overclock it.

    I'm still wishing for the rumored 5 GHz SKU to surface. I've rarely needed more than 4 cores, but a couple extra GHz always comes in handy. Even so, I'll not be upgrading until at least Skylake-E or perhaps Kaby-E.
  • Cerunnir
    Quote:
    Chris, how likely is it that a noctua NH-D15 would be able to cool these heat producing monsters if your h100i struggled and failed with the i7-6800k @4.4GHz. But a truly excellent review, even if it does show that there is little reason to go to broadwell-E over Haswell-E


    NH-D15 is arguably better or atleast equal to the H100i when it comes to cooling, and its noise levels is definatly lower both in load and while idle.

    http://www.relaxedtech.com/reviews/noctua/nh-d15-versus-closed-loop-liquid-coolers/2
  • arabesc
    Does it have support for ECC ram?
  • bit_user
    2258219 said:
    Does it have support for ECC ram?
    No. Buy a Xeon version, for that. It's practically the only difference. It's artificial product differentiation, known as "market segmentation".

    Here, you can find links to the specs of the CPUs mentioned in this article: http://ark.intel.com/products/family/79318/Intel-High-End-Desktop-Processors#@Desktop If you view their individual specs, you can see that none support ECC.

    Intel hasn't yet announced the E5-16xx v4 series CPUs, but you can turn up leaked specs with a bit of searching.

    And you'll need motherboard support, too.
  • cats_Paw
    Good review (excellent if its only the heads up for a more in-depth one).
    I have to say that I would love to have a 6 or even 8 core CPU but these prices and performances dont add up.

    In my country a 6700K and a 5820K are priced almost the same, but its still a hard choice (Do i want a "maybe" future proof 6 core that can be good for some work or a 4 core that is flat out faster and cheaper to build around for gaming?).
  • pyoverdin
    Am I correct in saying I could build a PC that's 5 FPS off the 6950X for it's price?
  • chaosmassive
    By Intel pushing out those super chip that I confused of Core, Lane, Cache, etc, etc
    can this "standard" of super CPU cores pushed all other i5 to 150 range and i3 150-100 ?
  • Samer1970
    Chris ,

    Can you please test the 8 cores i7 with HT turned off and compare it to the i7 4 cores at the same clock speed ?

    some games today use 8 threads , and the i7 6700k has 8 Virtual cores while the 6900k has 8 cores and if you turn HT off it will use full speed 8 threads ..

    compare it please ! and compare the Haswell-E 8 cores as well with HT turned off .

    compare i7 4 cores @ 4.4ghz HT (8 virtual cores) VS i7 8 cores @4.4 Ghz NO HT (8 true cores)
  • Samer1970
    AMD ZEN will win this round ... I was expecting the 10 Cores extreme to replace the old 8 cores one .. and that we have $450 28 lanes 8 cores ... but intel chosen to be greedy and ask $1700 instead of $1000 ...

    we need AMD to teach Intel a LESSON.
  • Yuka
    Thanks for the review!

    I would like to see the i7-6850K using a simpler cooling solution (CM 212X, maybe?) and pushing 2x970s or something that a regular non-rich gamer would try and get.

    It's hard to picture these CPUs as gaming power houses, but I do like the MOAR cores approach. F1 and Ashes show what the near future holds, so there's that.

    Cheers!
  • InvalidError
    73949 said:
    It's hard to picture these CPUs as gaming power houses, but I do like the MOAR cores approach. F1 and Ashes show what the near future holds, so there's that.

    Near future? I think we're 10+ years away from seeing the average game being capable of making meaningful use of that many cores. In the near-future, that figure is going to remain under 1% of new games.

    Even among games that do show scaling with extra cores, I'd be curious to see how much time the threads are burning busy-waiting on sync objects - this still counts as CPU usage in Task Manager but produces no useful work.
  • asd_1_
    Just look at ARM efficiency, Intel doesn't have a chance.
  • InvalidError
    2258283 said:
    Just look at ARM efficiency, Intel doesn't have a chance.

    The fastest ARM-based CPUs in mobile devices today are slower than the slowest current desktop i3 despite the i3 having one quarter as many cores.

    The reason why ARM is "so efficient" is because ARM-based CPUs still lack or massively scale down many power-hungry performance tweaks common in desktop CPUs. Until someone puts together an ARM CPU architecture with all those higher power optimizations, ARM will not become a credible threat to desktop CPUs.
  • ajpaolello
    Quote:
    AMD ZEN will win this round ... I was expecting the 10 Cores extreme to replace the old 8 cores one .. and that we have $450 28 lanes 6 cores ... but intel chosen to be greedy and ask $1700 instead of $1000 ... we need AMD to teach Intel a LESSON.


    Sorry I laughed a bit there. AMD can't touch up here although they can try. Plus the more you hype Zen up the bigger the disappointment will be.
  • Sasha dal Ponte
    So, 6700K is still better option for Adobe. Great to know :)
  • Yuka
    125865 said:
    Near future? I think we're 10+ years away from seeing the average game being capable of making meaningful use of that many cores. In the near-future, that figure is going to remain under 1% of new games. Even among games that do show scaling with extra cores, I'd be curious to see how much time the threads are burning busy-waiting on sync objects - this still counts as CPU usage in Task Manager but produces no useful work.


    Nah, not 10+ years away. Take a look at how new game titles are actually expanding on functionality that will require more processing power. I do agree it's hard to have a substantial argument about this, but my take on how the development of games will move forward is through VR and procedural generated content.

    Also, from the general programming perspective, the "busy/wait" issue arises when you're talking about single algorithms made parallel running, but when you're talking about thousands of threads, that is another topic. Context switches become way more expensive than the most hardcore "busy/wait" a single thread can incur into. Then you have, to your point, frameworks still being made more parallel.

    I don't want to go on a big tangent here, but that "it can't scale well beyond 8 threads" is contextualized on an old paradigm.

    Cheers!
  • $1700 for Core 10, Intel must be insane. I was hoping that 10 Core is going to be ~$1000 and 8 core finally become a bit affordable ~$600 but i guess Intel <mod edit> have to come up with a money to cover the failure with mobile chip. Well, <mod edit> you Intel i will stick with i7 3930k (6 Core).
  • dgingeri
    That sounds like my old 4930k, which is currently in my VM server, is better than these new chips. It can overclock to 4.6 at only 1.3V, and can reach 4.7 at 1.4V. What is the point of these new chips if they can't even clock as high as the older chips? This is pitiful.
  • elbert
    Broadwell-E has a major disadvantage in per core performance. Its game performance is well below the Skylake's 6700k. Guess this is why the game list was so lacking. The fact is Broadwell-E only gets a very small advantage over 5820k. The old 5930K is a much better deal than the 6850X due to PCI lane advantage. Mostly the prices are way to high. I suggest Intel drop prices to compete again the 5820k(6800X,6850X), and 5930K(6900X), and 5960X(6950X).
  • dgingeri
    Intel needs to do these things to resuscitate the PC market:
    1. Have more than 5% ipc improvement per generation, or be able to dial up the clocks better
    2. Put more PCIe I/O on the CPUs. The desktop chips should have 32 lanes, minimum, while the HEDT chips should have 64. This limitation of 16 on mainstream chips is BS, and putting more on the chipset is NOT going to make up for it.
    3. Lower prices. They are keeping the prices up and giving us nothing new except maybe using a little less power. What's the point to that?

    Very few people are willing to spend $1000 on a 10% increase in speed or a single feature addition. Intel is specifically the reason why the PC market has become stale. They've dug their own grave. These recent market tactics, especially with AMD lost in the background, are killing all reasons to upgrade PCs from one generation to the next.