Overclocking: Can Sandy Bridge-E Be Made More Efficient?

Test Configuration And Benchmarks

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LGA 2011 Platform
LGA 2011 PlatformIntel DX79SI, Chipset: Intel X79 Express, BIOS: 280B
LGA 2011 ProcessorIntel Core i7-3960X Extreme Edition (32 nm, Sandy Bridge-E), 6C/12T, 3.3 GHz, 6 x 256 KB L2 Cache, 15 MB L3 Cache, 130 W TDP, 3.9 GHz max. Turbo Boost
Memory4 x 4 GB DDR3-1333, Kingston KHX1600C9D3K2/8GX
GraphicsAMD Radeon HD 6850, GPU: Cypress (775 MHz), Graphics RAM: 1024 MB GDDR5 (2000 MHz), Stream Processors: 960
System DriveSamsung PM810, 256 GB, SATA 3Gb/s
Power SupplySeasonic X-760, SS-760KM
System Software & Drivers
Operating SystemWindows 7 Ultimate x64 SP1
Drivers & Settings
AMD Radeon DriverATI Catalyst 11.8 Suite for Windows 7
Intel Chipset DriverChipset Installation Utility Ver. 9.2.0.1030
Intel Rapid StorageVer: 10.6.0.1002
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Audio Benchmarks and Settings
BenchmarkDetails
iTunesVersion: 10.4.1.10 Audio CD ("Terminator II" SE), 53 min. Convert to AAC audio format
Lame MP3Version 3.98.3 Audio CD "Terminator II SE", 53 min convert wav to mp3 audio format Command: -b 160 --nores (160 Kb/s)
Video Benchmarks and Settings
BenchmarkDetails
HandBrake CLIVersion: 0.95 Video: Big Buck Bunny (720x480, 23.972 frames) 5 Minutes Audio: Dolby Digital, 48 000 Hz, Six-Channel, English to Video: AVC1 Audio1: AC3 Audio2: AAC (High Profile)
MainConcept Reference v2.2Version: 2.2.0.5440 MPEG-2 to H.264 MainConcept H.264/AVC Codec 28 sec HDTV 1920x1080 (MPEG-2) Audio: MPEG-2 (44.1 kHz, Two-Channel, 16-Bit, 224 Kb/s) Codec: H.264 Pro Mode: PAL 50i (25 FPS) Profile: H.264 BD HDMV
Application Benchmarks and Settings
BenchmarkDetails
7-ZipVersion 9.22 beta LZMA2 Syntax "a -t7z -r -m0=LZMA2 -mx=5" Benchmark: 2010-THG-Workload
WinrarVersion 4.01 RAR Syntax "winrar a -r -m3" Benchmark: 2010-THG-Workload
WinZip 16 ProVersion 16.0 Pro WinZIP GUI based Benchmark: 2010-THG-Workload
Autodesk 3ds Max 2012Version: 10 x64 Rendering Space Flyby Mentalray (SPECapc_3dsmax9) Frame: 248 Resolution: 1440 x 1080
Adobe After Effects CS5.5Create Video which includes 3 Streams Frames: 210 Render Multiple Frames Simultaneously: on
Adobe Photoshop CS 5.1 (64-Bit)Version: 11 Filtering a 16 MB TIF (15 000x7266) Filters: Radial Blur (Amount: 10; Method: zoom; Quality: good), Shape Blur (Radius: 46 px; custom shape: Trademark symbol), Median (Radius: 1px), Polar Coordinates (Rectangular to Polar)
Adobe Acrobat X ProfessionalVersion: 10.0.0 == Printing Preferences Menu == Default Settings: Standard == Adobe PDF Security - Edit Menu == Encrypt all documents (128-bit RC4), Open Password: 123, Permissions Password: 321
Microsoft PowerPoint 2010Version: 2007 SP2 PPT to PDF Powerpoint Document (115 Pages) Adobe PDF-Printer
BlenderVersion: 2.59 beta Syntax blender -b thg.blend -f 1 Resolution: 1920x1080, Anti-Aliasing: 8x, Render: THG.blend frame 1
MatlabR2011a, Internal Benchmark: 10 runs
Achim Roos
  • mayankleoboy1
    This article appeared on tomshardware.de weeks before.
    Reply
  • Combat Wombat
    Good to know!
    Reply
  • Yargnit
    What about trying to under-volt it at slight under-clocks to slight-overclocks. How much room is there to reduce it's stock voltage to gain better efficiency?
    Reply
  • billj214
    Was there an efficiency chart made for the Core i7 2600k or 2700k?
    Nice to know Intel doesn't just set the stock clock speed for just performance!
    Reply
  • Marcus52
    And then there's the Core i7-3820, which only sports four cores, but operates at a base clock rate of 3.6 GHz. Although this less-complex chip could probably hit higher Turbo Boost frequencies, Intel limits it to 3.9 GHz to keep it from outshining the top-end Core i7-3960X in single-threaded tasks.

    Did someone at Intel tell you that was the reason for a lower Turbo Boost limit, or did you just assume it?

    I think we should be careful of this kind of guess at another person's, or company's, reasoning. There could be some other cause for the limit - for example, they will obviously sell it for a lower price, so wouldn't a possible reason be they have looser binning specs to allow for chips that wouldn't make it under more strenuous tests through? (Remember, Intel, or any CPU manufacturer, doesn't warrant the product based on what it can be pushed to, and is generally going to provide it at a clock rate they feel is safe over time to guarantee.)

    I'm certainly not saying it is a bad assumption, what you said makes sense to me, but I do think there are enough other reasonable possibilities that I wouldn't have stated it as a fact unless I knew it to be.

    ;)
    Reply
  • Marcus52
    Thanks for the analysis!

    I do think articles like this are very important; those of us who overclock, especially when we turn off all the power-saving features in hopes of reaching that max stable a CPU can do, should be aware of how much money we are spending if we keep said OC. It's more than just the high end cooling solution.

    The people that bash higher capacity PSUs could also stand to learn a thing or two, here. An overclocked CPU can require a huge amount of peak power over and above what a stock CPU needs (349W measured here). An overclocked Sandy Bridge-E and an overclocked GTX 580 could require a peak power of 650W just considering those 2 components!

    A Kill A Watt or similar device is a great way to measure how much you actually spend a month operating your computer. You might be surprised.

    ;)
    Reply
  • lahawzel
    "Intel Core i7-3690X Extreme Edition"

    Tom's Parallel Universe Hardware.
    Reply
  • giovanni86
    Just a thought, so at 4.7Ghz the performance increase was only 16%? For being such a High overclock i was hoping for more then that. You guys literally upped the bar from stock clock to the OC clock by 1.4ghz, seems like a small increase in performance if you look at the amount of watts it takes.. Well at least its good 2 know my future billing of electricity will sure be expensive.. =P
    Reply
  • Naxos
    Does anyone spending 600-1k$ on a cpu really care about efficiency??
    Reply
  • cangelini
    Marcus52Did someone at Intel tell you that was the reason for a lower Turbo Boost limit, or did you just assume it?I think we should be careful of this kind of guess at another person's, or company's, reasoning. There could be some other cause for the limit - for example, they will obviously sell it for a lower price, so wouldn't a possible reason be they have looser binning specs to allow for chips that wouldn't make it under more strenuous tests through? (Remember, Intel, or any CPU manufacturer, doesn't warrant the product based on what it can be pushed to, and is generally going to provide it at a clock rate they feel is safe over time to guarantee.)I'm certainly not saying it is a bad assumption, what you said makes sense to me, but I do think there are enough other reasonable possibilities that I wouldn't have stated it as a fact unless I knew it to be.Hence the "probably." Of course, we don't know for sure, nor would Intel ever admit as such, but it's an educated guess nonetheless. =)
    Reply