Intel’s Core i5-8400: the new go-to gaming CPU


Intel’s new 8th Gen Core chips are out and there is much rejoicing. For the first time in about five years, Intel has made an unambiguous step forward with its mainstream CPUs. In short, they’ve bunged in an extra pair of cores across the board. Where once you had two cores or four cores, now you have four cores or six cores. Of course more cores don’t automatically translate into a better gaming experience. But I still think the new Core i5-8400 will become the chip of choice for gamers. Here’s why.

For a fuller overview of the new 8th Gen clobber, head over here. But the TL;DR is that the new range of CPUs is generally a very good thing indeed, albeit with the usual Intel-related caveats involving oddities in regard to product hierarchy (Hyperthreading in now exclusive to Core i7 models, as a for instance) and some pricing annoyances.

The other major take away is that regardless of whether you think there’s any point in going beyond four cores for gaming, 8th Gen Core hits the spot. That’s because the doubters can now get a fast four-core CPU for less cash and those who crave even more cores now have the option of six.

Personally, I’ll take the extra cores, and that’s where the new Core i5-8400 comes in. It’s the entry-level six-core effort of the new range and costs £180 / $190. That’s far cheaper than six cores have ever previously been available for from Intel.

But what’s it actually like to game with? In reality, little different to any reasonably high-clocked quad-core Intel processor of late. Even games that tend to reveal a modicum of CPU-related performance throttling, like the Total War series, don’t really throw up much by way of obvious benchmark deltas when you run games at the sort of settings at which people actually play games, rather than settings designed to isolate CPU performance at the cost of graphics quality.

Put it this way. Set the built-in benchmark in Total War: Attila to the popular 2,560 by 1,440 res, crank up the eye candy and let it rip courtesy of an Nvidia GTX 1080 and you get exactly the same average frame rate with everything from a Core i5-6600K through the new Core i9-7980XE 18-core monster. And indeed this new 8400 chip. The same goes for several other titles including Rise of the Tomb Raider, Deus Ex: Mankind Divided and more.

Use a less powerful graphics card and you’re only going to be more limited by GPU performance. In other words, it’s the graphics card capping performance, not the CPU. Which then begs the question of why you’d bother paying more for the extra cores of the 8400.

In short, it’s all about future-proofing. On paper, the 8400 does look rather modestly clocked. Officially, it packs a baseclock of just 2.8GHz, which is pretty crappy by today’s standards. In reality, it runs much faster than that. In fact, no matter what I threw at it, I couldn’t get it to run slower than 3.8GHz under load – even with all the cores maxed out running a synthetic stress test like Prime95.

corei5-8400-2All six cores in full flight at 3.8GHz

That said, I couldn’t get it to run faster than 3.8GHz at all. Intel claims a maximum Turbo boost of 4GHz for single threaded software. But even with water cooling, 3.8GHz is the best I saw. And this is a non-K model, so overclocking is off the menu.

But at 3.8GHz, it’s still quicker in single-threaded stuff than the fastest AMD Ryzen CPUs. And with six full-fat Intel cores, there’s headroom to spare for any future game that can make full use of more than four cores.

Since we’re talking AMD, at this rough price point you’re looking at a Ryzen 1600 or 1600X. Either will give you more multi-threading performance and, in all honesty, comparable performance in most games – maybe even slightly better performance in the odd title that scales well with available cores.

But like I’ve said, before, the problem with Ryzen is that just occasionally its clever modular architecture runs out of ideas and the result can be a stuttery gaming performance. Intel’s architecture remains more polished and consistent. It’s that simple.

Thus, the bottom line is this. If you’re even considering a chip like the 8400, you’re probably buying at least the CPU itself, plus motherboard and memory. At which point, the £10 premium for the 8400 over the £170-ish Core i3-8350K is utterly inconsequential and I’d argue even the £70 extra you have to pay over the entry-level Core i3-8100 quad-core model is pretty small fry if you’re hoping to get at least three years of gaming out of the thing, and maybe as many as five years.

So, that’s my logic here. Given my firm belief is that we wouldn’t have a lovely six-core Intel processor at this price at all were it not for AMD socking it to Intel with Ryzen, I’d far rather be recommending some kind of Ryzen CPU. It’s Ryzen that’s made this all possible.

But Ryzen isn’t the best all-round, sensible-money gaming option right now. Like it or lump it, that‘s the Core i5-8400.


  1. fray_bentos says:

    Nah. I’ll stick to my 4790K with all four paultry cores running at @4.8 GHz, thanks. Now, back to Cemu emulation where my single-thread performance will be enjoyed.

    • left1000 says:

      the i7-4790K is much more expensive than the i5-8400
      the comparable chip for you would be the i7-8700k

      • Imperialist says:

        Sadly, there hasnt been a real successor to the 4790k, mostly minor bumps in overall performance and almost no tangible difference. I want to see a real gamebreaker…

  2. Frosty Grin says:

    In short, it’s all about future-proofing.

    I’d be reluctant to buy a locked processor in the name of futureproofing. Especially now, when only Z370-based boards are available. You’re overpaying for overclocking but can’t use it.

    So I’d wait either for cheaper motherboards or for the 8500K. Or even the refreshed Ryzen coming early next year.

    • jeppic says:

      Yeah, I’m really struggling with the central thesis here.

    • Catterbatter says:

      That’s a big part of the value of Ryzen for me. (Some speculation ahead!) The 8th gen Intel parts require Z370, which is basically identical to Z270 but breaks compatibility with 7th gen processors. Intel has a history of doing this. Whereas if you’ve built around Ryzen, it’s likely you can just pop in a new processor three years from now and be done with it.

      • TheButler83 says:

        If I could give Catterbatters comment some sexeh time I would. Future proofing = dropping just a cpu upgrade every 2 years rather than an entire PC mobo build. That’s why I went for AMD and have had no regrets and great performance.

      • Optimaximal says:

        Surely Ryzen is so new and (seemingly) an inconsistent performer that putting faith in AMD *not* radically shaking up the chip sets, sockets and motherboards, thus breaking compatibility, shouldn’t be assumed?

    • SquarePeg says:

      Yes it seems to me that the 8100 and the 8600k are the gaming cpu’s of choice from Intel’s 8th gen. 8100 for it’s value proposition and 8600k for longevity. If the rate of performance (IPC) increases continues to remain low then the 8600k could well last 5-6 years or more.

      • Frosty Grin says:

        I think the 8400 is a value processor. It’s priced very well and will be a great choice for people unwilling to overclock. Getting a cheaper processor in the name of “value” isn’t a great idea when you can’t upgrade it without upgrading the motherboard and RAM. If you want something cheaper, just get a midrange Ryzen – because AMD will keep supporting AM4 motherboards for a few years, and you’ll be able to upgrade just the processor.

    • left1000 says:

      I agree, this cpu is so popular and well priced it’s sold out on a lot of stores. HOWEVER you NEVER future proof yourself with a locked processor. Overclocking after a couple years can extend the lifeblood of your computer a couple years, and all the risks of overclocking don’t matter when you’re only doing it to buy a little more time before buying something new anyways, if something goes wrong, you had always planned an upgrade anyways.

      • Frosty Grin says:

        Overclocking isn’t especially risky. I’d say it’s more of an investment – into a better cooler and faster RAM. Also an investment of time into stability testing.So it’s sensible to OC from the start.

  3. runadumb says:

    I wanted to go ryzen but coming from a 4670k it’s really a sideways step for most of my use cases. So, despite myself, I think I’m sticking with intel and feeding into a world devoid of competition.
    There’s a chance I’ll hold out until ryzen gen 2 but my pc is in need of a refresh soon.

    Now I need to decide between this and the 8700k.

    • fray_bentos says:

      Do you *really* need those extra cores? Single-thread performance of 4670K = 2,194 vs. 8700K = 2,764 vs. 4790K = 2,530, the later of which could be bought used and drop right into your existing motherboard (notwithstanding that fact that your existing CPU might already be running, or capable of running with a decent overclock).

      • fray_bentos says:

        I forgot to note that the single-thread performance of the 8400 = 2,119, less than your current 4.5-year old CPU. Progress.

      • runadumb says:

        I lost the silicon lottery on my CPU, it doesn’t overclock well. Also the pump on my AIO cooler died on me at some point 2 years ago and it was many a BSOD before I found the fault. I still get instability now and I’m not sure if I permanently damaged the CPU at that time.

        • MacPoedel says:

          You’re not answering why you couldn’t just buy a second hand Core i7 4790K to replace your 4670K. Your motherboard isn’t damaged (and your CPU isn’t either, thermal throttling happens precisely to prevent that, if you’re not getting any errors after having fixed your cooling issue, your CPU should be fine).

          Getting a Core i5 8400 is as much a “sidestep” as getting a Ryzen CPU. The main advantage Core has over Ryzen is clockspeed and the 8400 is clocked lower than most Ryzen CPU’s. If you really want to go Coffee Lake, maybe the 8700 (non K) is most interesting, it has the full 12 threads and clocks way higher than the 8400 (or 8600K), and it’s a bit cheaper (around €60 in my country) than the 8700K. If you’re not overclocking it’s probably the better choice (and frankly overclocking headroom is limited on the 8700K). But it’s still a shame that you need to pay the premium for overclocking and Multi GPU if you’re never going to use it.

  4. james.hancox says:

    What motherboard are you using that CPU with? A lot of recent ones turn on “all core boost” by default, which effectively forces the CPU to not drop down to base clocks.

  5. Carra says:

    Time to upgrade my i5 3570K? I’m sure it’ll run another year.

    • onodera says:

      I have the same rock and it has handled everything perfectly well so far. Upgrading it means buying new RAM and a mobo for no real benefit (I added new fast USB slots with a PCI-E card).

    • fish99 says:

      Same here. Mines still at stock too.

      Thing is the i5-8400 rates at 53% quicker than an i5-3570K, but it has 2 more cores so you’d expect that (6/4 = 1.5 or 150%). So single core performance is only slightly faster for the same (turbo) clock speed. Passmark reckons each core is only 4% quicker. And since very few games are going to take advantage of 6 cores, there really isn’t much gaming benefit. The 3570K is also still faster per core than a Ryzen 7 1800X.

      If the i5-8400 is a great gaming CPU, then so is the 3570K, still after all these years.

      link to

  6. elvirais says:

    But do we want to fund/promote the kind of “innovation” that means processors running hot at 90° with crappy default soldering?

  7. Raoul Duke says:

    “But like I’ve said, before, the problem with Ryzen is that just occasionally its clever modular architecture runs out of ideas and the result can be a stuttery gaming performance. Intel’s architecture remains more polished and consistent. It’s that simple.”

    I’m finding the tone of these articles kinda weird.

    So Ryzen is as fast or faster in gaming, but because of a completely unreferenced assertion that it’s got this stuttering issue, we should all keep throwing money at Intel despite them keeping us in a pit in their house for the last 5 years and occasionally lowering lotion down to us.

    Is this stuttering this actually a real problem? Is it simply a case of developers needing to catch up to the new architecture? Is Intel really more ‘polished’ or is it simply that they have been on top for so long that some games are lazily built to work on Intel chips rather than generic chips?

  8. rodan32 says:

    I’m pretty annoyed with Intel after building a new rig with a Z270 board earlier this year. It just feels like maybe Z270 was a little nerfed, and Intel had to scramble in response to Ryzen.

    I’m not mad that Intel is improving things with Coffee Lake; I’m more mad that they didn’t do that a year ago with Kaby Lake, when the technology was probably available to them. I’m content with my Kaby Lake rig, but it’s obnoxious to get caught not being forward-compatible anymore.

    • hurlster says:

      dude I feel your pain… bought a 6600k rig last year and now its a full replacment of mobo/cpu/ram to upgrade.

  9. Sakkura says:

    “Since we’re talking AMD, at this rough price point you’re looking at a Ryzen 1600 or 1600X.”

    Yeah, but the Ryzen chips can be put in much cheaper motherboards. And even when you save $50+ with a B350 board compared to Intel’s Z370, you get the ability to overclock, unlike with the Core i5-8400.

  10. floweringmind says:

    Intel has sat around not doing anything for 5 years and now we are supposed to buy something just because AMD released an amazing CPU? Combine that with lousy motherboard support because the options are so complicated. NAH. I am going to upgrade to a Ryzen 7 1800x.

  11. Zerpherion says:

    “In short, it’s all about future-proofing”

    No CPU is future proof, because motherboards, ram and sockets change on a regular bases.

  12. TotallyUseless says:

    Why was it said on this article that the i5 8400 only 2.8 Ghz whereas it actually goes up to 3.8Ghz? Is 3.8Ghz its boost clock?

    • teppic says:

      That’s the boost when only one core is being used and the others are idle. Intel is refusing to say what the others are.

  13. teppic says:

    You should check out AdoredTV’s video on this. With a low base clock and only a single core boost given, it’s quite possible on retail CPUs and midrange boards, this won’t even hit 3.5GHz on all cores, which would make it perform pretty poorly. There’s no chance of 3.8GHz on all cores without motherboard overclocking.

    Also, Ryzen at 4GHz (achievable by most CPUs) would outperform the Intel chip at 3.8GHz.

    • snv says:

      It is not that simple, sadly, because their architectures differ.

      There are other aspects like for example, how long is their pipeline?
      On one CPU it might need 12 ticks to finish an instruction on the other it might need 20. When you have a low framerate and neither your CPU or your GPU is running at 100%, chances are that somewhere a thread, that is running as fast as it can, still makes everything else wait. In that case more cores don’t help. (could also be a different bottleneck, like memory access or other stuff.. more cores don’t help here either).
      Stuff like that can make a difference, which is why back then in Athlon XP times AMD was better.
      Consider you have a branch in your code: If A do this, if B do that. Now you know if you need this or that after you found out if you have A or B and you only know that when the corresponding instruction went all the way through the CPU and if it took 20 ticks for that than the CPU might have calculated useless stuff for 20 ticks and all that has to be thrown away.
      Intel got faster and faster because it made their pipelines longer and longer, so it had a problem with lots of discarded instructions back then (this scenario happens all the time in programs).
      That’s what hyperthreading is all about. It was Intel’s band aid: When you let a core do something completely unrelated each other tick you only have wasted half your ticks in the described scenario.

      Excuse my rambling

      • teppic says:

        Ryzen is only a few per cent behind in IPC compared to Coffee Lake. That means that if the 1600 (6 core 12 threads) is running at 4GHz vs an i5 that runs all cores at 3.8GHz it’s going to beat it under almost all circumstances, especially anything multithreaded.

        But on top of that, cheaper boards are very unlikely to manage 3.8GHz on all cores because the CPU has a TDP of 65W and that’s too limiting without automatic motherboard overclocking (manual is disabled). It has a base clock of 2.8GHz which means Intel will only guarantee 2.8GHz on all cores.

        We’ll have to wait and see if cheap/midrange boards and retail i5s can get anywhere near 3.8GHz on all cores.

  14. MacPoedel says:

    I don’t get where this is coming from. The 8400 is clocked lower than most Ryzen CPU’s and since most of the single threaded performance difference between Core and Ryzen comes from the higher clockspeeds, the 8400 isn’t really faster. For roughly the same money a Ryzen 5 1600 can be bought that has:
    – 12 threads vs 6 threads
    – Roughly the same clockspeed (except max boost is a little low on stock settings)
    – Can be overclocked, most 1600’s can run 3.8GHz on ALL cores and not just a few like the 8400. That doesn’t even require special cooling or a good motherboard.
    – Runs on cheaper motherboards (and can still be overclocked on those!)
    – Can be upgraded by new AM4 processors until 2020 (given how rushed Coffee Lake’s platform is, I bet Cannon Lake won’t even work on Z370 motherboards, but even if it does, there’s no way whatever comes after that will be compatible)
    – Has a better boxed cooler

    What the 8400 puts against that is that out of the box it’s a little faster, but in practice, when the GPU is the bottleneck, as is stated in the article, the 1600 is just as fast for gaming as the 8400. And the Z370 chipset/socket 1151 platform is a little more forward than B350/X370 (chipset has PCIe 3.0 lanes instead of 2.0 for example, if you want more than 1 PCIe SSD).

    I think the 8600K or 8700(K) are way more interesting, the 8700K is a better gaming CPU than the Ryzen 7 1700 in the same price bracket, the 8400 has much fiercer competition and if performance is comparable, picking the red team is a no brainer instead of settling for another 10 years of stagnance.

  15. Marclev says:

    In fact, no matter what I threw at it, I couldn’t get it to run slower than 3.8GHz under load – even with all the cores maxed out running a synthetic stress test like Prime95.

    Why would you expect it to run slower under load? Surely the more you throw at it, the more it has to work, the faster it has to run.

    • Sakkura says:

      Hitting thermal or power ceilings is what would make it slow down; in addition, Intel usually has lower turbo boost ceilings when more cores are active.

  16. Marclev says:

    Got an old i7-2600k and it still runs the latest AAA games perfectly fine.

    That thing’s 6 years old now, I suspect until the next generation of consoles come out, it won’t struggle with anything.

    So what’s the point?

    • Ronlaen says:

      Running the same CPU with a GTX 1080 FTW and can run anything I throw at it with 3440×1440 res 100 Hz G-Sync. This is the first gen that I’m tempted to upgrade but even then it’s hard to see the point.

  17. waltC says:

    Intel is never a good choice for “future proofing”…;) The company changes sockets like you change socks, pretty much. AMD, otoh, has a long and demonstrated history of staying with the same sockets through several cpu upgrades (AM3+, etc.) As well, the PCIe lanes situation is a lot better with AMD, too. Intel is pretty much just warmed over old-hat these days–knee-jerk in response to AMD. AMD is just getting started with Ryzen. Intel’s going to really have to sweat to remain competitive–no more lazy monopoly for them…;)

    • wackazoa says:

      Multiple comments including the one right above yours says youre wrong.

  18. qudrun says:

    You forgot to mention that Intel no longer gives us information on how their cpus perform turbo boost with all cores. This probably means that different i5-8400 will perform very differently and that they cant guarantee anything but the base clock, which is 2.8ghz and the turbo boost for 1 core.

    Also it is important to understand that the 8400 is basicly the crappiest parts that was not good enough to be a 8600k or 8700k. This means that it is more likely to require a z-motherboard to perform to its best, as power delivery is better. It is safe to assume that you wouldnt reach 3.8ghz on all cores on a budget motherboard.

  19. wackazoa says:

    Not to downgrade AMD, I truthfully don’t fanboy either (I have 1 Pentium G4400 PC, 1 FX8320 PC, and 1 Athlon 860K PC), but don’t count too hard on the sticking to AM4 for “long term”. DDR5 is supposedly coming out late 2018 or 2019. That would be the biggest wrench in the socket.

    Either way Im looking forward to building more PC’s with both AMD and Intel in the future so the competition is looking great to me.

    • Sakkura says:

      The DDR5 spec will be released in 2018, but it won’t hit consumer hardware right after that.

      For comparison, the DDR4 spec was finalized in 2012, but Intel only added support for that on their high-end X99 platform in 2014, and on their mainstream platform in 2015.

      So assuming a similar timeline, DDR5 would be finalized in 2018, and it would be supported by mainstream platforms around 2021.

  20. Expcen20 says:

    This article just plain upsets me, too many “I thinks” and opinions to write that final line as if the competition is null and void. Regardless of my personal input, check out this YouTube researcher’s review for something with more facts.
    link to

  21. one2fwee says:

    So, since my comments seem to be spam filtered due to links, here it is again without the link to adoredtv’s video. I don’t see why my posts should be spam filtered for links yet no one else’s seem to.

    There is no guarantee that the 8400 will reach or maintain anywhere clockspeed about its standard rating of 2.8GHz

    Tech press have been given high quality silicon samples and the end consumer will no doubt not be so lucky.

    Adoredtv’s video is a good summary.

    Seriously though, even when the parts from AMD and Intel and AMD and Nvidia are even you always recommend Intel or Nvidia.

    So you recommend the company that has been stifling innovation in the industry and driving up prices even though the competitor’s product is very comparable in gaming and even better in multithreading.

    Games are only going to get more and more multi-threaded and the consoles use AMD chips which high core counts. This can only help Ryzen performance compared to Intel in the long run and yet you talk about Intel being the future proof option.

    It’s a joke.

    I don’t care for either of the 3 companies – the GPU market especially is a joke.
    I care about the consumer and for years, by far, AMD (and ATI) have been a lot more pro consumer than Intel and Nvidia. If the opposite became true then I would support whoever was most pro consumer. Even AMD are increasing prices for GPUs now that Nvidia have “normalised” higher prices for lower end parts.

    You games journalists really show what side you’re on and it’s not that of the consumer.

  22. Lars Westergren says:

    > Which then begs the question

    It “raises the question”. “Begging the question” is a rhetorical fallacy, a form of circular reasoning.