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Intel Core i7-7820X Skylake-X Review

Test Setup & Overclocking

Test Systems

We're using MSI's X299 Gaming Pro Carbon AC for testing. We disabled the all-core Turbo Boost feature to ensure a level playing field.

Skylake-X processors can scale beyond DDR-4000, but we settled on DDR4-3200 for our overclocked config to match the transfer rates of AMD's overclocked Ryzen CPUs.

In the U.S. lab, we attained a 4.6 GHz overclock at 1.28V. This proved stable for 12 hours under AIDA's FPU, cache, and CPU tests. Temperatures hovered ~85°C during the non-AVX load. We were also able to run Prime95 for extended periods, but the processor frequently engaged in aggressive throttling due to thermal constraints. As such, we used an AVX offset to lower the clock rate during AVX-enabled workloads.

Trying to push beyond 4.6 GHz required excessive voltage, which in turn generated even more heat. That's no good with Skylake-X, so we stuck with the safer, more stable settings. Budget in a closed-loop liquid cooler at the very least to keep Core i7-7820X from throttling at stock frequencies. More aggressive overclocking begs for a custom open loop.

We introduced our new test system and methodology in How We Test Graphics Cards. If you'd like more detail about our general approach, check that piece out.

The only updated components in our German lab are the CPU, system memory, motherboard, and new cooling solution, so we'll just provide a quick overview in the following table:

Test Equipment & Environment
SystemGermany Intel LGA 2066Intel Core i9-7900X, i7-7740XCore i5-7640X, Core i7-7820XMSI X299 Gaming Pro Carbon AC4x 4GB G.Skill Ripjaws 4 DDR4-2600AMD Socket AM4AMD Ryzen 7 1800X, 1700X, 1600X, 1500XMSI X370 Tomahawk2x 8GB G.Skill Ripjaws V DDR4-3200Intel LGA 2011v3Intel Core i7-6900KMSI X99S XPower Gaming Titanium4x 4GB Crucial Ballistix DDR4-2400Intel LGA 1151Intel Core i7-7700K, i5-7600KMSI Z270 Gaming 72x 8GB Corsair Vengeance DDR4-3200 @2400 MT/sAll SystemsGeForce GTX 1080 Founders Edition (Gaming)Nvidia Quadro P6000 (Workstation)1x 1TB Toshiba OCZ RD400 (M.2, System)2x 960GB Toshiba OCZ TR150 (Storage, Images)Be Quiet Dark Power Pro 11, 850W Power Supply Unit (PSU)Windows 10 Pro (All Updates)Be Quiet Dark Power Pro 11, 850W Power Supply Unit (PSU)Windows 10 Pro (Creators Update)U.S.Intel LGA 2066Intel Core i9-7900X, Core i7-7820XMSI X299 Gaming Pro Carbon AC4x 8GB Corsair Vengeance DDR4-2666 @ 2666 and 3200 MT/sIntel LGA 2011v3Intel Core i7-6900KASRock X99 Extreme44x 8GB Corsair Vengeance DDR4-2666 @ 2666 and 3200 MT/sAMD Socket AM4 AMD Ryzen 7 1800X, 5 1600XMSI X370 Xpower Gaming Titanium 2x G.Skill FlareX DDR4-3200 @ 2666 (stock), and 3200 MT/s Intel LGA 1151 Intel Core i7-7700K MSI Z270 Gaming M7 2x G.Skill FlareX DDR4-3200 @ 2400 All EVGA GeForce GTX 1080 FE 1TB Samsung PM863 SilverStone ST1500, 1500W Windows 10 Creators Update Version 1703
CoolingGermanyAlphacool Eiszeit 2000 ChillerAlphacool Eisblock XPXThermal Grizzly Kryonaut (For Cooler Switch)USCorsair H115iCorsair H100i v2Arctic MX4
MonitorEizo EV3237-BK (Workstation, Office, HPC)
Power Consumption MeasurementContact-free DC Measurement at PCIe Slot (Using a Riser Card) Contact-free DC Measurement at External Auxiliary Power Supply Cable Direct Voltage Measurement at Power Supply 2x Rohde & Schwarz HMO 3054, 500MHz Digital Multi-Channel Oscilloscope with Storage Function4x Rohde & Schwarz HZO50 Current Probe (1mA - 30A, 100kHz, DC) 4x Rohde & Schwarz HZ355 (10:1 Probes, 500MHz) 1x Rohde & Schwarz HMC 8012 Digital Multimeter with Storage Function
Thermal Measurement1x Optris PI640 80Hz Infrared Camera + PI Connect Real-Time Infrared Monitoring and Recording


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  • cknobman
    Just want to say the Ryzen 7 1800x isnt $500 anymore and has not been for weeks now.

    The processor is selling for $420 or less. Heck I bought mine yesterday from Fry's for $393
    Reply
  • artk2219
    19984543 said:
    Just want to say the Ryzen 7 1800x isnt $500 anymore and has not been for weeks now.

    The processor is selling for $420 or less. Heck I bought mine yesterday from Fry's for $393

    Not to mention the fact that you can find the 1700 for even less, and more than likely be able to bump the clocks to atleast match the 1800x. Microcenter was selling them for 269.99 last week.
    Reply
  • Ne0Wolf7
    At least they've done something, but it still too expensive to sway me.
    Perhaps full blown profesionals who need something a bit better than what Ryzen has right now but can go for an i9 would appreciate this, but even hen he/she/it would probably wait to see what threadripper had to offer.
    Reply
  • Scorpionking20
    So many years past, I can't wrap my head around this. Competition in the CPU space? WTH is this?
    Reply
  • Houston_83
    I think the article has some incorrect information on the first page.

    "However, you do have to tolerate a "mere" 28 lanes of PCIe 3.0. Last generation, Core i7-6850K in roughly the same price range gave you 40 lanes, so we consider the drop to 28 a regression. Granted, AMD only exposes 16 lanes with Ryzen 7, so Intel does end the PCIe comparison ahead."

    Doesn't Ryzen have 24 lanes? Still under intel but I'm pretty sure there's more than 16 lanes.
    Reply
  • artk2219
    19984718 said:
    I think the article has some incorrect information on the first page.

    "However, you do have to tolerate a "mere" 28 lanes of PCIe 3.0. Last generation, Core i7-6850K in roughly the same price range gave you 40 lanes, so we consider the drop to 28 a regression. Granted, AMD only exposes 16 lanes with Ryzen 7, so Intel does end the PCIe comparison ahead."

    Doesn't Ryzen have 24 lanes? Still under intel but I'm pretty sure there's more than 16 lanes.

    Ryzen does have 24 lanes, but only 16 are usable, 8 are dedicated to chipset and storage needs.
    Reply
  • JimmiG
    19984740 said:
    19984718 said:
    I think the article has some incorrect information on the first page.

    "However, you do have to tolerate a "mere" 28 lanes of PCIe 3.0. Last generation, Core i7-6850K in roughly the same price range gave you 40 lanes, so we consider the drop to 28 a regression. Granted, AMD only exposes 16 lanes with Ryzen 7, so Intel does end the PCIe comparison ahead."

    Doesn't Ryzen have 24 lanes? Still under intel but I'm pretty sure there's more than 16 lanes.

    It does, but only 16 are usable, 8 are used for chipset and storage needs.

    16X are available for graphics as 1x16 or 2x8.
    4X dedicated for M.2
    4X for the chipset that's split into 8x PCI-E v2 by the X370 and allocated dynamically IIRC
    Reply
  • Zifm0nster
    Would love to give this a chip a spin.... but availability has been zero.... even a month after release.

    I actually do have work application which can utilize the multi-core.
    Reply
  • Math Geek
    does look like intel was caught off guard by amd this time around.

    will take em a couple quarters to figure out what to do. but i'm loving the price/performance amd has brought to the table and know intel will have no choice but to cut prices.

    this is always good for the buyers :D
    Reply
  • Amdlova
    Why we have overclocked cpus ons bench but dont have power compsumation! this review is biased to intel again !? are tomshardware fake news ?
    Reply