Lenovo ThinkPad X1 Carbon 7th gen review (Core i7, FHD & UHD screens)


  1. Matteo B

    August 23, 2019 at 4:03 am

    One of the best ways to limit the CPU temperature is to disable the hyperthreading in the BIOS. In most of the daily use, it is totally unuseful and, without it, the CPU energy consumption (and heating) is a lot lower. You can probably squeeze much better performances overall because of the higher frequency every single core can achieve. I'm really surprised nobody really test CPUs in this configuration.

    • Derek Sullivan

      August 23, 2019 at 4:42 am

      I just ran cinebench r20 with hyperthreading disabled. Single core stayed about the same at 426 points which makes sense since that test only uses one thread. The multicore score dropped from 1544 to 1286 though. And all 4 cores still hit 99C and throttled.

      • Matteo B

        August 23, 2019 at 5:14 am

        Makes some sense, but depends on the real use. Does CineBench r20 takes in consideration this kind of environment? If in real use the load of all 4 cores is always at 100%, the CPU will throttle anyway. But when this happens in real use? The chance of throttling on all cores should be reduced with hyperthreading disabled (when you try to overclock a CPU, you can usually hit higher frequencies with HT disabled just because it stays a little cooler, and what you gain in frequency is worth the loss of HT to increase single core performances). This is true on games for example. To me it seems that this kind of CPUs are already at the top frequency/time limit no matter if the stay a little cooler or not.
        Btw it is a nice laptop!

    • Andrei Girbea

      August 23, 2019 at 9:40 am

      It would depend on the workload. If it's something that balances well over 8 threads, you won't get better performance this way. The CPU normally does a pretty good job adjusting its speed within the thermal and Power-limit constraints. Undervolting is something I recommend, but otherwise I'd leave things on auto. The only time I actually got better performance with various manual limitations is on combined CPU + GPU threads on a laptop with a shared thermal module, in which case limiting the CPU leaves more headroom for the GPU to run at higher clocks.

  2. DavidC1

    August 25, 2019 at 8:19 pm

    Are you actually testing the battery life, or are you calculating using the watt numbers you get?

    • Derek Sullivan

      August 25, 2019 at 9:13 pm

      It's calculated based of average wattage during use for a set period of time.

  3. Kirk Diaz

    August 26, 2019 at 1:42 am

    Thanks for the well written review. I'm going to order the i5 version (with 16GB memory) which I read in another review would probably perform close to the same as the i7 in many cases due to the i7 throttling to keep heat down.

    Plus, for my usage I do not think I need an i7. If I was doing any tacks that needed processor power I would use my desktop.

    I have a question on the FHD, I'm trying to decide on that screen (400 nits) for the brightness and better battery life or the WQHD for a sharper picture (maybe more color accurate?) but I'm not sure about the 300 nits.

    What I wondered was during your testing did you notice any excessive ghosting which can be present with low power screens, or did you find the ghosting to be minimal?


    • Derek Sullivan

      August 26, 2019 at 4:26 am

      Hi Kirk. I didn't notice any ghosting. I think the fhd screen is fine, especially at 14". 22" is the optimal viewing distance for the, where you start to notice the pixels.

      I haven't seen the qhd, but I'd take the fhd for the power savings and the added brightness.

      • Kirk

        August 26, 2019 at 6:20 pm

        Thanks Derek, I was leaning that way so great to get some confirmation.

        Going to order this week, good pricing right now with the current sales.


    • OSSO

      September 2, 2019 at 7:28 pm

      This is odd as another article clearly states that 400 nits low power display from Lenovo develops terrible ghosting. Unless 400 nits on X1C is very different from the one on T490S (which I doubt).

      PWM is not used on our panel and backlight bleeding is no problem, either, but the response times are very long. This is most noticeable when you move the cursor or scroll through documents/websites (ghosting)


      • Derek Sullivan

        September 2, 2019 at 7:44 pm

        It's the same panel. They list the model number.

        NBC has equipment to measure the actual response time, so those numbers are pretty legit. It's not an ideal response time, but I didn't notice it during my use. Then again, I wasn't gaming on this laptop either, so it's no surprise I couldn't tell. It's not an easy thing to notice unless you're particularly sensitive to it or are playing games that require a fast time.

  4. Adam Riese

    August 26, 2019 at 4:10 pm

    Will you test other Thinkpads like the T495 as well?

    • Derek Sullivan

      August 26, 2019 at 6:51 pm

      I'm not sure yet. It depends on what Lenovo has available to send me.

  5. Vincent

    September 3, 2019 at 12:02 am

    Thank you for your fine review.

    On the Lenovo.com forums, many folks with the X1C7 have indicated that they get essentially no sound at all from the top facing speakers, i.e. the new speakers north of the keyboard which necessitated the moving of the on/off switch.

    Folks who have experimented with struggling to hear ANY sound whatsoever coming from those speakers came up empty! Zero sounds coming out from those speakers. One guy who found a youtube video which is a Dolby demo video said on THAT one specific video, he was able to hear a little bit of sound coming from those speakers. Besides that, none whatsoever. Others concurred.

    May I please ask if you might be able to discuss this lack of any audio from the new speakers (upward facing north of the keyboard) issue please?

    Thank you sir in advance.

    • Derek Sullivan

      September 3, 2019 at 12:17 am

      At first I thought the same thing. In fact, in my first draft it was actually a complaint because I had no idea what the holes were for.

      Once I figured out they were tweeters, I spent a lot more time and figured out that they only play very high frequency sounds. And it's definitely not as loud. This might be by design, but I'm not sure. The speakers as a whole sounded good so I didn't mind that they aren't as loud as the bottom.ones. I'd rather have full, clear sound than something that's pushed too far and sounds crackly. I've definitely seen my fair share of failures for quad speakers on laptops.

      • Vincent

        September 3, 2019 at 12:47 am

        As a long time audiophile, and as someone who just cancelled my X1C7 order (my arrival date is for Oct 16th though i ordered on Aug 1st!!), and i'll reorder hopefully over the next week or two when the Comet Lake processors will appear on the customize column on lenovo's order page, i'm more than curious about how/when the top facing speakers will produce sound.

        One good test would be to choose a piece of music that we know has a lot of cymbals, triangles, and such high pitched percussive instruments. These high frequencies of "ding ding ding…" and such would most likely emanate from the top facing speakers.

        May I please request that if possible, that you kindly please perform such a test, please? Thank you Derek in advance.

        Most appreciated!

      • Derek Sullivan

        September 3, 2019 at 12:52 am

        Hi Vincent,

        Unfortunately I sent my review units back in already. Sorry about that.

      • Tom

        October 12, 2019 at 3:58 pm

        This is a pretty standard approach used by various speaker designers and it gets applied in many guises. Essentially low frequency (bass) sounds take more power to create at a volume that we can hear, so techniques are used to increase the efficiency. These include letting the sounds fire towards a hard surface as in this case, or putting a box with an open tube on one side to impedance match with the air. These efficiency improvements can come at a cost, and this can include a poor group delay response ('ringing on') or uneven frequency response. Thankfully, our ears aren't too sensitive to this for bass sounds, so designers can get away with it. For high frequency (treble) sounds this isn't the case – in most scenarios you want the speakers facing you, since the ear is most sensitive to imperfections in this frequency range.

  6. Nat

    November 7, 2019 at 9:22 am

    Could you compare this to the Lenovo 720S 14"? The 8250u version has been a solid all-rounder for me but with lots of little things that could be improved.

    • Derek Sullivan

      November 7, 2019 at 4:11 pm

      I can't unfortunately because I've never actually had a 720S in my hand. In general though, Ideapads are less robust than the Thinkpad lineup and are maid more for the mainstream crowd. Hence the cost difference. If you're super careful with your machines, an Ideapad can last a very long time. But it will definitely show it's age with typical use.

    • Andrei Girbea

      November 8, 2019 at 12:47 pm

      Our review of the 720s is available over here: https://www.ultrabookreview.com/17425-lenovo-ideapad-720s-review/ . Not really the same kind of laptop, but good value for the money.

  7. luis

    January 8, 2020 at 4:16 pm

    Hi Dereck.

    1st of all, sorry for bottering you with this, but I didn't know who to ask, and, as you deal with some laptops at your work, I figured you might be able to help me.

    I'm Luis from Portugal, an ultrabookreview avid reader since 2015.
    2 weeks ago, I bought a new laptop, to replace my oldie Toshiba Satellite r630 from 2011, which I never upgraded to Windows 10.
    The laptop's full package (an Asus ZenBook UM431 btw) seems great by now (thin, so well-built it seems a solid peace of metal), but, randomly, from time to time, the SmartScreen.exe process decides it needs 20-25% of CPU power, turning the fan on and eating my battery. (I'm running Windows 10 version 1903, because I didn't have time to upgrade to 1909 yet.)
    As I said before, I've never used Windows 10 before, and in Windows 7 I used the Microsoft Security Essentials AV, which never did something like that.

    Now, the questions. You review lots of laptops, and you always achieve great battery life on those who are built to deliver it. Do you review all laptops as you get them? Or do you make some changes in configuration? Did you ever stumble on a laptop which behaved like mine? Because I'm sure that, would you review my laptop now, It wouldn't deliver the battery life it's suposed to deliver.
    Microsoft always touted it's newer OSs as lighter than the previous ones, but I'm not seeing it.

    Again, sorry for bottering you, and hope you can help me with your experience.

    Keep up your great work.


    • Andrei Girbea

      January 9, 2020 at 12:51 pm

      Updated the latest drivers and bios for Asus's website, as well as the latest Windows updates, etc. Then try to google this exact problem and look for fixes, if it still persists.

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