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Intel Core I7 6950X Extreme Edition Broadwell-E Overclocking Review

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Intel Core i7 6950X Extreme Edition Broadwell-E Overclocked: Overclocking

The story starts with you laying out some serious cash to step into one of Intel's Extreme Edition fully unlocked X-SKU processors and you just want more performance. Something akin to throwing a blower on a high performance sports car, because 550 naturally aspirated horsepower just is not enough. But is it ever? The key difference between that high horsepower car and the Broadwell-E Core i7 6950X is that at least we get the added horsepower for free, relatively speaking of course. Time has a cost for all of us.

On Broadwell-E, Intel has brought a few new tools to the table that help change the overclocking dynamic. We get by-core overclocking that comes in handy when your best core is identified, and AVX ratio offset that allows the user to drop the voltage and clock speed ratio under heavy work loads. By working with these tools, you can maximize by-core performance and dynamically reduce the core clock speed and voltage under heavy loads to keep the processor within its thermal limits. They are both pretty cool tools to use when you sit down and spend the time to manage cores and how they clock. Along those lines, ASUS has a cool little utility called the ASUS Thermal Control Tool that can help configure performance inside the OS environment. While I could paraphrase ASUS' own DIY article, the best way to fully understand it is to take a quick read through here. Usually, each manufacturer has its own proprietary overclocking and tuning utility that can be installed for tuning while in the operating system. Those do well to get solid gains without beating on the processor too hard. For those that demand more, there is always overclocking via the UEFI BIOS.



For this round of testing, I used the ASUS Sabretooth X99 to tune the Broadwell-E 14nm Core i7 6950X. ASUS' UEFI is pretty familiar and is one of the best laid out UEFI implementations. To get the most out of the CPU, I used traditional methods to reach 4342MHz on the core, using 1.305v applied to the cores. I started out by setting the X.M.P. profile for the G.Skill Trident Z memory and started tweaking the core clock speed and cache ratios to find the maximum speed I could get into the BIOS comfortably. I found out pretty quickly that the cache ratio was not going to run 1-1 with the core clock ratio, as I topped the 39x ratio on the core and cache bus. In fact, using the 38x ratio was marginally stable and required more voltage to the core and cache bus, raising the thermal load.

To go any higher on the core clock ratio I had to step the cache ratio down to 37x. This allowed me to push the clock speed on the core a bit higher to 4300MHz. I was able to push to 4342MHz changing the bclock to 101MHz with a clock speed multiplier of 43 as the outer limits of the thermal solution I was using. However, 1.305v proved to be a bit too much for the 240mm radiator I used to cool the processor, so I added a 360mm radiator to the equation and temperatures came a little closer back in line, but still reached the TJMax and started throttling the processor. Even with a good cooling system, getting the load through the IHS and thermal compound does not happen quick enough to prevent throttling.

At that point, I had to drop the voltage down a bit to 1.295v and shoot for the fastest speed I could get while staying below the throttle point of the chip. While 4342MHz was stable through all the testing, it just got too warm and would throttle, hurting performance when pushed. Dropping the voltage and clock speed to a prime95 stable 4275MHz proved a bit better for the long term thermal health of the chip. To get there, I dropped the multiplier to 42 and increased the bclock to 101.8MHz. After finding this speed to be both thermally tenable and stable, I decided to try overclocking the best core higher while keeping the balance of the cores at the 4275MHz clock speed. It seems that bumping that core up to 4444MHz did not produce any errors in my stability testing regimen, so this may open up some additional performance when you set core affinity to take advantage of the higher clock speed.





Below are some screenshots of the settings I used in the ASUS UEFI BIOS to overclock this CPU. The second image will show which of the cores is the identified best core on this particular processor. In this case, Core 9 is the best of the bunch.




Intel Core i7 6950X Extreme Edition Broadwell-E Overclocked: Testing Setup

To validate that level of performance delivered by Intel's Broadwell-E Core i7 6950X, I will be running it and its comparison products through OCC's test suite of benchmarks, which include both synthetic benchmarks and real-world applications. The gaming tests will also consist of both synthetic benchmarks and actual gameplay, in which we can see if similarly-prepared setups offer any performance advantages. The system will receive a fully updated, fresh install of Windows 7 Professional 64-bit edition, in addition to the latest chipset drivers for each board and GeForce drivers for the NVIDIA GTX 770. To ensure as few variables as possible, all hardware will be tested at their stock speeds, timings, voltages, and latencies, unless otherwise stated. Turbo Boost will be disabled on all processors to make a fair comparison without skewing results. After stock speed testing, each processor will then be overclocked as much as possible, while still maintaining full stability.


Testing Setup: Intel Socket 2011 V-3


Testing Setup: Intel (Socket 1151)


Testing Setup: Intel (Socket 1150)


Testing Setup: Intel Socket 2011


Testing Setup: AMD (Socket AM3+)


Maximum Core Clock Speed:

Each CPU has been tested for stability at the listed overclocked speeds. These clock speeds will represent the level of performance shown by the overclocked scores in the testing.




  • Scientific & Data:
  1. Apophysis
  2. WinRAR
  3. Geekbench 3
  4. Bibble 5
  5. Office 2010
  6. POV-Ray 3.7
  7. ProShow Gold
  8. HandBrake .99
  9. Sandra 2014 SP2
  10. AIDA64
  11. Cinebench R15
  12. X.264 Benchmark
  13. PC Mark 8
  • Video:
  1. Metro: Last Light
  2. Batman: Arkham Origins
  3. 3DMark


Intel Core i7 6950X Extreme Edition Broadwell-E Specifications:

  1. Intel Core i7 6950X Extreme Edition Broadwell-E: Overclocking & Testing Setup
  2. Intel Core i7 6950X Extreme Edition Broadwell-E Overclocked Testing: Apophysis, WinRAR, Geekbench, Bibble 5
  3. Intel Core i7 6950X Extreme Edition Broadwell-E Overclocked Testing: Office 2010, POV-Ray, ProShow Gold, Handbrake
  4. Intel Core i7 6950X Extreme Edition Broadwell-E Overclocked Testing: SiSoft Sandra, AIDA64
  5. Intel Core i7 6950X Extreme Edition Broadwell-E Overclocked Testing: Cinebench 15, X.264, PCMark 8
  6. Intel Core i7 6950X Extreme Edition Broadwell-E Overclocked Testing: Gaming & Conclusion
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