Hi. We use cookies to ensure that we give you the best experience on our website. Click OK and continue to use the site.  OK

Ultrabook reviews, guides and comparisons

Intel Core i5-8250U (Kaby Lake-R, 8th generation) benchmarks and early impressions

By Andrei Girbea , updated on September 11, 2017

As of late August 2017 Intel announced the first quad-core eight-thread platform designed for ultra-portable computers. The CPUs in this line are sold as 8th generation processors, although in reality they are an update of the 7th generation hardware line and are called Kaby Lake-R (efresh). According to Intel’s new naming policy, the 8th gen series includes these KabyLake-R CPUs already released, but also the Coffee Lake and Canon Lake CPUs that will be released in the future. However, that shouldn’t matter much to you as a potential buyer.

The platform’s particularities on the other hand should, and we’ve already spent time with two laptops (Acer Spin 5, Asus Zenbook UX331UN) built on the entry-level processor of the 8th gen line, the Core i5-8250U. The paragraphs below include our impressions, benchmark results and comparisons to the existing Core i5-7200U and i7-7500U CPUs.

But first, here’s what you should know about the Kaby Lake-R platform. It includes 4-core 8-thread Core i5 and i7 processors built on a revised 14+ nm lithography, with a TDP of 15 W and support for up to 32 GB of up to DDR4-2400 memory. They also integrate the same Intel HD 620 graphics chip that’s part of the dual-core KabyLake processors. However, in order to accommodate the 2x number of cores, the default speed per core is lower on the quad-core models, with Turbo Speeds compensating for that with most loads, and as you’ll see below that’s both a fast performing and an efficient solution.

The Kaby Lake-R CPUs will make it into a large numbers of ultraportable laptops and mid-tier full-size notebooks, with or without dedicated graphics. We compiled a full-list of all these laptops in this dedicated article.

With that in mind, let’s get to the main topic of this article, the Core i5-8250U processor. You’ll find the important technical specs below.

And here’s how it compares to the dual-cores and the Core i5-7300HQ, the closest quad-core alternative available until now.

i5-8250U (Ark)
i5-7200U (Ark)
i5-7300HQ (Ark)
i7-7500U (Ark)
Litography14 nm14 nm14 nm14 nm
TDP15W15W45W15W
Cores/Threads4/82/44/42/4
CPU Base Frequency1.6 GHz2.5 GHz2.5 GHz2.7 GHz
CPU Max Turbo3.4 GHz3.1 GHz3.5 GHz3.5 GHz
Cache6 MB3 MB6 MB4 MB
Max Memory
32 GB32 GB64 GB32 GB
GraphicsIntel HD 620Intel HD 620Intel HD 630Intel HD 620
Graphics Speed300- 1100 MHz300- 1000 MHz350- 1050 MHz300- 1050 MHz
PCIe lines12121612
Price$297$281$250$393

Alright, so compared to the i5-7200U and the i5-7500U, the newer i5-8250U has two more cores and four more threads, more Cache memory and slightly faster Intel HD 620 graphics capable of reaching marginally higher Turbo Speeds. The base CPU frequency on the other hand is much lower, but the Turbo Speeds are comparable or improved over the dual-core i5s and i7s, and that’s why the i5-8250U is a match for the dual-cores in terms of single-core performance and a big step-up in multi-core activities. More about that in a bit.

Compared to the i5-7300HQ, the i5-8250U is a lot more efficient, gets four more threads and more cache. As far as performance goes, well, here’s what to expect.

While I don’t believe synthetic benchmarks make much sense for real-life use, they’re the best way to actually fair these CPUs one against the other. We ran a couple of CPU benchmarks, and the results are below.

CPU Benchmarksi5-8250U S1
i5-8250U S2i5-7200Ui5-7300HQi7-7500U
Cinebench R15 CPU486 cb527 cb~326 cb~512 cb~338 cb
Cinebench R15 CPU – Single Core136 cb143 cb~128 cb~142 cb~143 cb
Cinebench R11.5 CPU5.66 pts5.98 pts~3.7 pts~5.7 pts~3.8 pts
Cinebench R11.5 CPU – Single Core1.58 pts1.64 pts~1.5 pts~1.5 pts~1.7 pts
Geekbench 4.0 – Multi Core1224313220~6790~9300~8070
Geekbench 4.0 – Single Core41944053~3630~3720~4150
Passmark – CPU test79207945~4600~6800~5200
x264 HD Benchmark 4.0 – Pass 230.4 fps42.23 fps~21.6 fps~32.3 fps~21.6 fps
x264 HD Benchmark 4.0 – Pass 1137.93 fps156.24 fps~113 fps~155 fps~117.1 fps
3DMark – FireStrike Physics74417918~4640~6370~5430

The i5-8250U results are based on two review units (S1, S2) we’ve spent time with. Keep in mind they’re both pre-production samples and these numbers might actually improve with better optimized drivers down the line. Both worked fine though and I’m comfortable to say that’s mostly what we should expect from this CPU.

The other results are based on our reviews and the averages for those CPUs from notebookcheck.net, as they have a larger pool of reviews in their database.

Overall, the i5-8250U improves on all the dual-cores on multi-core performance and it beats the i7-7500U in terms of single-core performance in most tests. It’s neck in neck with the i5-7300HQ CPU in multi-core benchmarks though, despite having four extra threads, and that’s because the i5-8250U cannot maintain 3.4 GHz Turbo Speeds in continuous full loads (Cinebench, x264 Bench). I noticed the same behavior on both our samples, as you can see in the pictures below.

The CPU maintains high Turbo speeds for a short while, which is corroborated with a package TDP of 25 W or higher, but after a few seconds it drops to the standard 15 W TDP and the frequencies drop to 2.2 – 2.3 GHz.

That means that if you need the best option for multi-core performance, the 45 W Core i7 HQs are still the ones to get right now, but the i5-8250U is there next to the i5-7300HQ in most cases, while requiring a third of the power.

We also ran a couple of GPU benchmarks for the Intel HD 620 chips on the i5-8250U configurations and we’re comparing the results to the average HD 620 results from notebookcheck.net.

GPU Benchmarks GraphicsHD 620 S1HD 620 S2HD 620 average
3DMark 11P1741P1862P1628
3DMark – FireStrike Graphics10171021916

Nothing unexpected here, the results on the i5-8250U are a little higher than the norm, as the chips can reach slightly higher Turbo Speeds.

There’s also the topic of gaming on an the i5-8250U configuration to discuss, but I can’t draw any firm conclusions based on our two samples. What I can tell you is that the CPU wasn’t be able to maintain 3.4 GHz speeds in recent games on either of the units, with a significant drop on the configuration that relied solely on the i5-8250U and the Intel HD 620 integrated chip (S1 in the pics below), and a smaller loss on a configuration that came with dedicated Nvidia graphics on the side (S2 in the pics). That makes sense, as the GPU integrated withing the processor is inactive in this latter case and as a result the actual cores can run at higher frequencies, not having to share energy with the GPU, within the TDP restrictions.

I’d reckon you’ll also be interested on the matters of temperatures, noise and battery life for the KabyLake-R configurations, and while I don’t want to generalize and I encourage you to read the specific reviews for the devices you’re interested in, I can say that these are on par with what we’ve seen on dual-core Kaby Lake builds in the last year.

Wrap-up

With all these in mind, if I were in the market for a high-performance ultraportable right now, I see no reason why I wouldn’t pick one of the KabyLake-R models. I would note that I can’t yet conclude on the gaming experience, due to the drop in core speeds we noticed on one of our samples, but if I were into gaming I wouldn’t rely on the Intel HD graphics anyway, but rather go with a thin-and-light with dedicated Nvidia graphics.

For everyday multitasking and demanding loads that put stress on the CPU though, the KabyLake-R Core i5-8250U is an obvious pick over the dual-core i5-7200U and i7-7500U, but also a better balanced and much more efficient alternative to the quad-core i5 HQ processors. The i5-8250U is also just a tad more expensive than the i5-7200U and about $100 cheaper than the i7-7500U, so configurations built around it should have a pretty fair price as well.

Of course, the i5-8250U is just the entry level chip in the KabyLake-R series, with higher clocked i5s and i7s also available for those interested in even more power in this small and efficient package. I’ve yet to spend any time with these for now, so we’ll talk about them in future posts.

Bottom point, the quad-core Core U CPUs are one of the most significant upgrades we’ve seen on thin-and-light ultraportable laptops in the last years, and they’ll make their way into a bunch of devices in the second half of 2017 and later on. Here’s a full list, and stay around for reviews and updates. That aside, the comments section is wide open, so get in touch if you have anything to add, any questions or any feedback.

Andrei Girbea, Editor-in-Chief at Ultrabookreview.com. I never liked carrying big laptops around and that fueled my passion for mobile computers back in the 2000s. Things have changed much since then, but I'm still interested in the topic and in the meantime I've owned and tested hundreds of thin and lights, so I know a thing or two about them. You'll find mostly reviews and guides written by me here on the site.

22 Comments

  1. johndoe

    August 28, 2017 at 10:13 am

    Thank you for such an honest review.
    I found the information I needed to make a decision whether to buy or not the laptop with KabyLake-R. Miracle has no happened.

  2. James

    August 28, 2017 at 5:23 pm

    Thanks for the review. Is it safe to say that for video editing it will be better to buy now I7 7700HQ over i7 8650u?

  3. Ddd

    August 30, 2017 at 1:30 am

    Have you done any testing with a eGPU yet? Can these or the i7 quad core U version power a higher end GFX card for gaming?

    • Andrei Girbea

      August 30, 2017 at 2:45 am

      I'll have a post on a laptop with this i5 and Nvidia MX150 graphics. Perhaps some OEMs might pair these quad-core 15W CPUs with gtx 1050s, but I doubt we'll see them on full size gaming laptops. Once portability is not a concern, the 45W quad-cores make more sense performance wise.

      • DM

        August 30, 2017 at 4:50 pm

        There is a weird rumor that the refresh for Legion Y720 will keep the discrete GPUs, but replace the HQ cpus with quad core U's: liliputing.com/2017/08/lenovos-kaby-lake-r-lineup-includes-new-yoga-ideapad-legion-laptops-leaks.html

        • Andrei Girbea

          August 31, 2017 at 2:39 pm

          Yeah, I've heard, but from what I've seen these configs come with AMD graphics, not with the 1060 that's available on the standard y720.

  4. Marco

    September 1, 2017 at 4:52 am

    Hello

    Very good article.

    One comment: could it be possible to update the table as the iGPU line for the 8th generation is called UHD, not HD?

    Intels is really serious now regarding its GPU…

    • Andrei Girbea

      September 2, 2017 at 12:49 pm

      I will, but it's pretty much the same chip, just a minor bump in frequency.

  5. CuriousK

    September 1, 2017 at 1:36 pm

    Sorry, but i'm just a little curious. If I'm getting a laptop for graphic design purposes (Adobe Illustrator, Photoshop & basically Adobe Suites). Which of the processor (i7-8550U & i7-7700HQ) would perform better?

    • Andrei Girbea

      September 2, 2017 at 12:51 pm

      the i7-7700HK, but it would depends on your loads and activities. For basic things, the U will do as well, for heavier use that put as train on the CPU, the HQ is the better pick.

      • CuriousK

        September 2, 2017 at 2:12 pm

        May I know what are some examples of heavier use?

        • Andrei Girbea

          September 3, 2017 at 4:39 am

          edit a longer movie in Premiere, edit a bit batch of photos in Premiere, apply complex effects in Photoshop, run virtual machines, etc.

  6. Evgeni Popov

    September 5, 2017 at 6:08 am

    The i5 7300hq is with 6GB of chache not 4GB. The bus speed of the i5 7300hq is 8 GB/s and for the i5 8259u is 4 GB/s and the PC lanes 16 vs 12 for the i5 8250u.
    Will teh Lenovo Y520 be released with the new i5 8250u , when and what will be the price?
    What will be the better decision to buy now a Lenovo Y520 with i5 7300u or wait for a new with i5 8250u?

    • Andrei Girbea

      September 6, 2017 at 12:36 pm

      Thanks, updated. Not sure about the Legion, but if I'd want the laptop for demanding loads and even gaming, I'd probably get the i5-7300HQ configuration. As an allrounder, the Core U i5 is better balanced: still fast enough, but more efficient.

  7. Jarecki

    September 11, 2017 at 7:20 am

    UX331UN???? When? :)

    • Andrei Girbea

      September 11, 2017 at 12:30 pm

      Finishing it up right now. So today or tomorrow.

  8. Perry

    September 11, 2017 at 4:07 pm

    Hi there,

    I really love your review.

    I was thinking to buy a MacBook Pro 13 to replace my old MacBook Air. But I see the 8250U with 40% increase in performance, sounds amazing. What about the battery life? Will the 2 more cores increase power consumption?

    Do you think it worth the wait to buy a MBP 13 next year? Probably another 6 month waiting…….

    Thanks

    • Andrei Girbea

      September 11, 2017 at 4:57 pm

      You should read some user reviews. The 13-inch MBP is a nice laptop, but expensive. As long as you can live with a Windows laptop, you'll probably find better value for the money in this camp.

      These CPUs down-clock when they don't have to run at full-speed and have the same TDP as the previous dual-core ULVs. In theory, that means they don't need much power, and based on the few laptops I've already reviewed with the i5-8250U, that's also true in real use.

      • Perry

        September 11, 2017 at 5:33 pm

        Thanks for getting back to me.

        I have used to the mac os system in the past 5years, and dont think I can go back to windows right now.
        The current MBP13 equipped with the 7267U, compare with the 8250U, what's the real world difference? The base clock of the 8250U only has 1.6GHZ, will this become an issue compare with the 3.1ghz 7267U?

        • Andrei Girbea

          September 12, 2017 at 4:06 am

          Multi core performance is better on the quad-cores like the 8250U and 8550U, but it will be hard to actually notice that in real life. Performance shouldn't be a concern on the 13 MBP imo, my nits are with the keyboard and battery life. I haven't used it extensively so I'm not going to say more thant hat, but you'll find a lot of opinions about it online and on Youtube.

          As for waiting for the update, I don't know when that's going to happen, but probably not that soon. There are two more Intel CPU series scheduled for the next 6 months and Apple are usually not very speedy to upgrade their devices

Leave a Reply

Your email address will not be published. Required fields are marked *