Intel Core i5-8400 Review: Six Cores On A Budget

By Igor Wallossek, Paul Alcorn
last updated

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How We Test

Test Notes

MSI motherboards, like many others, feature a default Enhanced Turbo feature that allows the processor to run at its maximum Turbo Boost bin on all cores, at all times. For all practical purposes, this is the same as overclocking. The feature only applies to K-series processors, though, so it isn't a factor in our Core i5-8400 testing.

We paired our sample with a Z370-based motherboard, which does support faster memory. Sticking with Intel's official specification, we used DDR4-2666 modules to represent the data rates you'll have access to once B- and H-series motherboards surface.

As far as we can tell on our MSI motherboard, Intel isn't allowing BCLK adjustments. That means the Core i5-8400 locks us down to stock settings.

Comparison Products
AMD Ryzen 5 1600X
AMD Ryzen 5 1500X
AMD Ryzen 5 1400

Test Systems

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.

Only our CPU, memory, motherboard, and cooling subsystem are different. The table below summarizes the hardware we used to generate our data.

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Test System & Configuration
HardwareGermany Intel LGA 1151 (Z370):Intel Core i5-8600K, Core i5-8400MSI Z370 Gaming Pro Carbon AC2x 8GB Corsair Vengeance DDR4-3200 @ 2666AMD Socket AM4 WorkstationAMD Ryzen 5 1500X, Ryzen 5 1600X, Ryzen 5 1400MSI X370 Tomahawk4x 8GB G.Skill TridentZ DDR4-3200 @ 2667 and 3200 Intel LGA 1151 (Z270)Intel Core i5-7600K, Core i5-7400MSI Z270 Gaming 72x 8GB Corsair Vengeance DDR4-3200 @ 2400 and 3200All 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 SupplyWindows 10 Pro (Creators Update)U.S.Intel LGA 1151 (Z370):Intel Core i5-8600K, Core i5-8400MSI Z370 Gaming Pro Carbon AC4x 8GB G.Skill RipJaws V DDR4-3200 @ 2666 and 3200 AMD Socket AM4 AMD Ryzen 5 1500X, Ryzen 5 1600X, Ryzen 5 1400MSI X370 Xpower Gaming Titanium2x 8GB G.Skill RipJaws V DDR4-3200 @ 2667 and 3200 Intel LGA 1151 (Z270)Intel Core i5-7600K, Core i5-7400 MSI Z270 Gaming M72x 8GB G.Skill RipJaws V DDR4-3200 @ 2666 and 3200 All EVGA GeForce GTX 1080 FE 1TB Samsung PM863 SilverStone ST1500-TI, 1500W Windows 10 Creators Update Version 1703
CoolingGermanyAlphacool Eiszeit 2000 ChillerAlphacool Eisblock XPXThermal Grizzly Kryonaut (For Cooler Switch)
MonitorEizo EV3237-BK
PC CaseLian Li PC-T70 with Extension Kit and Mods Configurations: Open Benchtable, Closed Case
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, 500 MHz Digital Multi-Channel Oscilloscope with Storage Function4x Rohde & Schwarz HZO50 Current Probe (1mA - 30A, 100 kHz, DC) 4x Rohde & Schwarz HZ355 (10:1 Probes, 500 MHz) 1x Rohde & Schwarz HMC 8012 Digital Multimeter with Storage Function
Thermal Measurement1x Optris PI640 80 Hz Infrared Camera + PI Connect Real-Time Infrared Monitoring and Recording
Acoustic MeasurementNTI Audio M2211 (with Calibration File, Low Cut at 50Hz) Steinberg UR12 (with Phantom Power for Microphones)Creative X7, Smaart v.7 Custom-Made Proprietary Measurement Chamber, 3.5 x 1.8 x 2.2m (L x D x H) Perpendicular to Center of Noise Source(s), Measurement Distance of 50cm Noise Level in dB(A) (Slow), Real-time Frequency Analyzer (RTA) Graphical Frequency Spectrum of Noise


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Igor Wallossek
29 Comments Comment from the forums
  • velocityg4
    I'd be interested in knowing. Under what circumstances can you get it to hit 3.8Ghz reliably under a 6-core load? That is quite a spread.

    If one was to delid the CPU and use a decent CPU cooler. Would it reliably maintain the max turbo boost when the CPU usage demands it? Is the stock heatsink and decent case cooling plenty?

    On another note. It is time for the return of the Turbo button. That would be pretty sweet to click the button and manually have the CPU jump between 1, 2, 4 and 6 cores at their respective boost frequencies or down to standard. I know it isn't necessary as it is all automated and that wasn't the purpose of the Turbo button. Some people just like manual control. Plus old time computer geeks would get a kick out of it.
    Reply
  • AgentLozen
    This is a very neat chip at it's price point. Very little has changed between Kaby Lake and Coffee Lake except for the core count. Luckily for Intel, those added cores make all the difference.

    This CPU would sit nicely on a budget system. It's a shame that there are no inexpensive motherboards that it could fit into like the conclusion of this article states.

    If you didn't plan to overclock, this is the best CPU on the market for gaming and general productivity.
    Reply
  • The_King
    We have AMD to thank for all these budget cpu's from Intel, and you all know why! So thank you AMD.
    Reply
  • rwinches
    No, you can't have charts based on FPS or seconds or related to MSRP. Drivers update, Prices change, Memory Speeds Increase and price lowers, MB prices are wide range.

    It is known that Some games work better for AMD when AMD GPUs are used. Game FPS can be dramatically improved by changing just one parameter. Test results that are milliseconds or a few seconds or frames faster are irrelevant and subject to variations in real world use on systems that are not clean installs and have other SW installed and running.
    Reply
  • 10tacle
    20307991 said:
    No, you can't have charts based on FPS or seconds or related to MSRP. Drivers update, Prices change, Memory Speeds Increase and price lowers, MB prices are wide range.

    I don't understand your point. This is a review of the 8400 and comparing it to other CPUs only. Memory, motherboards, and all the other variables are you talking about in a full PC build are irrelevant to this chart comparison. They have to establish a constant standard across the spectrum, and they did so.

    20307991 said:
    It is known that Some games work better for AMD when AMD GPUs are used. Game FPS can be dramatically improved by changing just one parameter. Test results that are milliseconds or a few seconds or frames faster are irrelevant and subject to variations in real world use on systems that are not clean installs and have other SW installed and running.

    Again, they are using a single standard across the spectrum comparison. Of course there are infinite combinations of hardware that can game change a little. The bottom line here is that among every major tech review website, all of Intel's chips are better for gaming than Ryzen. The only exception is when dealing with beyond 1080p gaming like QHD or UHD where it's mostly on the GPU. People who buy this chip are the perfect candidate for a 144Hz 1080p G-sync or Freesync monitor.
    Reply
  • lotusmotors
    Glad I didn't waste money on a 1600x.
    Reply
  • elbert
    Compared to the Ryzen 1600 with a B350 its $50 higher. That is a higher video card level. IE get the 8400 with a 1050ti the Ryzen budget would get a 1060 3GB. Intel needs their B360 motherboards for the 8100 and 8400 to ever be a budget winner.
    Reply
  • hardwarefox1234
    Has the author even bothered to look at the street prices for the CPUs??

    Core i5 8400:

    https://www.newegg.com/Product/Product.aspx?Item=9SIA7HN6HF3442&cm_re=i5_8400-_-9SIA7HN6HF3442-_-Product
    http://www.microcenter.com/product/486090/core_i5-8400_coffee_lake_28_ghz_lga_1151_boxed_processor
    http://www.ncixus.com/products/?sku=142465&vpn=BX80684I58400&manufacture=Intel

    The lowest price is $249.99!

    The Ryzen 5 1600 is much cheaper:

    https://www.newegg.com/Product/Product.aspx?Item=N82E16819113435&cm_re=ryzen_5_1600-_-19-113-435-_-Product
    http://www.microcenter.com/product/478826/Ryzen_5_1600_32GHz_6_Core_AM4_Boxed_Processor_with_Wraith_Spire_Cooler
    http://www.ncixus.com/products/?sku=139481&vpn=YD1600BBAEBOX&manufacture=AMD
    https://www.amazon.com/AMD-Processor-Wraith-Cooler-YD1600BBAEBOX/dp/B06XNRQHG4/ref=sr_1_3?s=pc&ie=UTF8&qid=1508952175&sr=1-3&keywords=ryzen+5+1600

    Price is $199.99~$219.99!

    Then if you add the price of the B350 motherboards,they start at a lower level than the Z370 ones.
    Reply
  • hixbot
    Why did you label section 10, overclocking, cooling and temperature? There's no overlocking on this chip? I would have like to see at least an attempt at Bclk overlcock with a mobo that has a clock generator.
    Reply
  • TJ Hooker
    I really wish more reviewers would look at what sort of boost clocks the i5 8400 can sustain under load, with the stock cooler as well as aftermarket. From what I know you could typically assume past Intel CPUs would operate at or near max turbo almost indefinitely, but with a 50% increase in core count and such an unusually wide gap between base and boost clocks (not unlike their mobile CPUs), I'm curious how Coffee Lake will behave in that regard.
    Reply