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

CPU Computing & Rendering Performance

CPU Performance: Workstation

Many modern suites include modules that are based exclusively on computing and simulations. This means we need to go beyond just 3D workstation performance. However, software packages like SolidWorks don’t scale perfectly based on core/thread count. Consequently, even quad-core processors keep up if they run at high-enough frequencies and support SMT.

This is also seen in a direct comparison between the Core i5-7600K and Core i5-8400. The latter does not benefit much from its extra cores and larger aggregate cache.

Frequency is all that counts in Creo 3.0. Compared to Intel's Core i5-7600K, the company's -8400 only derives small advantages from its two additional cores.

Clock rate and core count both matter in 3ds Max 2015, so the Core i5-8400 lands slightly behind Intel's Core i5-8600K.

Though an overclocked Ryzen 5 1600X is close on Coffee Lake's heels, the -8400 costs less and facilitates higher performance.

The CPU Composite benchmark makes extensive use of rendering, though, so AMD's Ryzen 5 appears much stronger. Now it's an overclocked 1500X going up against (and beating) Core i5-8400. A lack of Hyper-Threading support likely hurts Intel here.

CPU Performance: Photorealistic rendering

Final rendering doesn’t require a CPU that's good at everything. Rather, this task wants efficiency and fast parallel computation.

When it comes to pure rendering, the Core i5-8400 offers best-in-class performance. It is only challenged by AMD's pricier Ryzen 5 1600X.

The console variant of LuxRender confirms that none of Intel's Core i5s can compete with the Ryzen 5 1600X, stock or overclocked.

Last, but not least, we take a look at Blender in several different workloads.

The first one, with a sample size of 200 pixels, confirms what we saw in the preceding benchmarks: Core i5-8400 trails the Ryzen 5 1600X by a big margin. In fact, a stock 1600X has little trouble beating the Core i5-8600K by more than 20%.

The results obtained from SPECwpc’s Blender loop look similar, even though this benchmark presents a somewhat different task consisting of more than just rendering. Ryzen 5 takes a big lead over Core i5.

The Core i5-8600K pushes upwards as the amount of pure rendering decreases. The rest of the results look similar, though, and Core i5-8400 suffers from its lack of Hyper-Threading.

This trend intensifies as our benchmark incorporates tasks other than photorealistic rendering. Core count isn't the sole determiner of performance; IPC throughput factors in as well. The Core i5-8600K even leads, followed by Intel's Core i5-8400.

Ryzen 5 1600X jumps to the front once again. Core count matters, of course, but operating frequency is also a critical variable.

Intel’s Core i5-8400 offers acceptable performance in semi-professional applications, so it's more than just a gaming CPU. However, the Core i5 series lacks Hyper-Threading support, which is apparent in highly parallelized workloads. Those tasks tend to favor AMD's Ryzen chips.

Then again, this throws the potent six-core chips right where Intel wants them. If they fared too well, Core i5 would cannibalize sales of the pricier Core i7s.

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  • 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.
  • 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.
  • The_King
    We have AMD to thank for all these budget cpu's from Intel, and you all know why! So thank you AMD.
  • 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.
  • 10tacle
    Anonymous 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.

    Anonymous 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.
  • lotusmotors
    Glad I didn't waste money on a 1600x.
  • 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.
  • 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.
  • 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.
  • ATI9800Pro
    There's a typo in the temperature charts ; it reads "Core i7-8400".
  • John__Titor
    Seems like a very solid CPU, but no way would I list the included cooler as a pro. It's cheap garbage. At the very best it's neutral. AMD has set a new standard for stock coolers that should be encouraged for budget processors.
  • PaulAlcorn
    Anonymous said:
    <snip>

    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.


    I second the vote for the return of the Turbo button. Good times!
  • PaulAlcorn
    Anonymous said:
    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.


    Good catch, fixed. Intel has been pretty good at locking out BCLK overclocking even on boards with an external clock generator. We'll keep an eye out for any further attempts at this, though.
  • Nintendork
    VELOCITYG4
    Why even bother having to delid a cpu and change tim to actually have a working cpu instead of simply buying the cpu king Ryzen 5 1600-1600X and forget about having to patch intel's mess?
  • HERETIC-1
    Hi Paul,
    When you mention-comes with a free cooler-would have been nice if you could
    have tested it-perhaps running Handbrake,and also then checked what turbo
    speeds it could maintain with stock cooler.
    As a budget 6 core I feel that is typical use,

    I feel for gaming-those that can't afford 8600K are likely to go for the cheaper
    4 core 8350K,which will probably be faster than 8400 in most games............
    If we get a non K 8600 next year-that could be interesting...........
  • Papatom
    I have looked at Tom's coverage of both Ryzen and Coffee Lake.
    From what I could see, there is a strong preference to show intel products in a better light.

    1. Pricing. THG chooses platform/processor alone costs as they see fit; any sane choice would include at least the cooling solution and, perhaps, motherboard into this. Not at THG though; I expect this to change when cheap intel mobos arrive.
    2. Cooling. You guys here seem to use good cooling (as in: expensive and performing), yet you do not inculde the costs into the equation. Combined with better thermals of competitive AMD offerings, this is smelly.
    3. Hand-picked benchmarks - blender and lux-what? included, POV-ray and Cinebench excluded. You guessed it, AMD hardware tends to have upper hand in the latter (excluded ones).
    4. Looking thru fingers at contest rules. RX 480 was over the TDP, you named and shamed it. i9s were over their respective TDPs, you failed to clearly state so.

    I no longer find this website serving just information for me to make educated purchasing decision.
    I am fed up. From a regular reader back in '90 thru early this decade, I decided to leave this site for good.
  • mapesdhs
    "... the 8400's multi-core Turbo Boost bins get a lot more aggressive than Core i5-7400's."

    Just curious, if the CPU can handle all six cores at 3.8 anyway, why is the base clock so much lower? Why not just set the base clock to 3.8 anyway? Or is it because it could only sustain 3.6 if the cooler was up to the task? If so, then Turbo has morphed into a sort of pseudo-Intel-sanctioned auto oc'ing.

    Also, since the 6-core turbo level starts off from a higher frequency, the percentage gain of the higher levels vs. the 6-core turbo level is lower than the inter-level gains for the old 4-core, which is if anything IMO somewhat less imppressive.

    Ian.
  • TJ Hooker
    Anonymous said:
    I have looked at Tom's coverage of both Ryzen and Coffee Lake.
    From what I could see, there is a strong preference to show intel products in a better light.

    1. Pricing. THG chooses platform/processor alone costs as they see fit; any sane choice would include at least the cooling solution and, perhaps, motherboard into this. Not at THG though; I expect this to change when cheap intel mobos arrive.
    2. Cooling. You guys here seem to use good cooling (as in: expensive and performing), yet you do not inculde the costs into the equation. Combined with better thermals of competitive AMD offerings, this is smelly.
    3. Hand-picked benchmarks - blender and lux-what? included, POV-ray and Cinebench excluded. You guessed it, AMD hardware tends to have upper hand in the latter (excluded ones).
    4. Looking thru fingers at contest rules. RX 480 was over the TDP, you named and shamed it. i9s were over their respective TDPs, you failed to clearly state so.

    I no longer find this website serving just information for me to make educated purchasing decision.
    I am fed up. From a regular reader back in '90 thru early this decade, I decided to leave this site for good.

    1. They addressed the fact that you'll need to pair the 8400 with a more expensive Z370 mobo for the time being in the first page, as well as in the conclusion.
    2. Ok this I kind of agree on. In the review they use a massive 420mm rad AIO cooler or a compressor cooler water loop, but then conclude that a basic air cooler is fine for cooling, and don't address stock cooler performance at all.
    3. AMD performs just fine in the benchmarks they did pick though. The 1600X outperforms the 8400 (and usually the 8600K) in both Luxrender and Blender.
    4. They called out the RX 480 for violating the PCIe spec on the max current/power that could be drawn from the motherboard slot (and even then they said this probably wouldn't be an issue 99% of the time, IIRC). That's not the same as going over TDP. TDP was never supposed to be an accurate measure of power consumption anyway. Apples to oranges.