Review Index:

Lenovo ThinkPad X240 Ultrabook Review: A Philosophical Shift

Subject: Mobile
Manufacturer: Lenovo

Performance - Introduction, Processor, Application Performance

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The X240 features the same CPU as the T440s we reviewed before it, and in fact, apart from a larger (double capacity) SSD and 8 GB RAM (versus the T440s’ 4 GB, both single-channel), it’s nearly identical in terms of configuration.  As such, we should expect to see very similar overall system performance in our synthetic benchmarks, excluding ones which directly correlate with those areas of discrepancy (i.e., storage benchmarks and those heavily dependent on GPU memory).

In terms of comparisons to other models, the two most obvious candidates would be the T440s and the X230 we reviewed a year ago.  Both provide interesting context, as the T440s is so similar in overall configuration, and the X230 is the last X series machine to date with full-voltage components.  Our benchmarks will answer the question of just how much performance we’ve sacrificed in the switch to a ULV chipset, as well as how that translates to power conservation—and ultimately, whether it was worth it.

Before we get to the actual benchmarks, let’s take a look at how the system handles stress.  Under full CPU load (using FurMark’s CPU Burner component), we recorded a maximum system temperature (after 30 minutes of stress) of 77°C, while the CPU held its frequency at a stable 2.3 GHz (the maximum Turbo Boost for two-core operation).  That’s encouraging, as it means that CPU-intensive tasks should be no trouble for the X240.

In precisely the same way as the T440s (and even the Flex 14 before it), however, the instant any significant degree of GPU load is introduced, the machine immediately throttles both CPU and GPU.  The maximum internal temperature was 74.1°C, but the GPU only managed to reach 700 MHz consistently.  The CPU, on the other hand, dropped its clock rate to around 900–1000 MHz, which is—again—the same thing we saw with the T440s.  The biggest difference here is that the internal temperature is around 8°C warmer than the max temperature we recorded during stress with the T440s (nevertheless, both machines throttle in nearly identical fashion).  As we expected, our final test of combined GPU and CPU stress also provided identical results, with the CPU throttling to 800–900 MHz and the GPU reaching just 600 MHz.

Performance – Processor

The X240’s Intel Core i5-4200U CPU is the same as that in the T440s we reviewed.  This is a 1.6 GHz Haswell ULV model that can Turbo Boost up to 2.6 GHz (2.3 GHz for two active cores).  Meanwhile, unlike the X230’s 35W TDP CPUs, the i5-4200U features a low TDP of just 15 W.

SiSoft Sandra Processor Benchmark

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Here we have our first example of how the TDP affects the overall CPU performance.  Our results from SiSoft Sandra are nearly identical to the T440s and the Flex 14, and even very similar to that of the ThinkPad Twist (which featured an Intel Core i5-3317U).  As we noted in our T440s review, the X230’s results are far an above those of the X240 thanks to its more powerful (and more power-hungry) CPU: in this case, it’s 33% and 48% higher than the X240 in Whetstone and Dhrystone, respectively.  That’s a significant margin if you’re planning on any sort of CPU-heavy activity.

Cinebench R11.5

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Although both units beat the Flex 14 on OpenGL performance (likely due to a difference in driver versions), the X240 and the T440s are essentially neck-and-neck in the Cinebench tests.

Futuremark Peacekeeper

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Since Peacekeeper cares as much about the browser as it does the actual hardware, it’s worth always taking its results with a grain of salt.  Still, the X240’s total score of 2585 is right in line with the T440s and a little above the Flex 14.

Application Performance

CPU benchmarks notwithstanding, let’s see how well the X240 fares in terms of general performance.

PCMark 7

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PCMark 7 is always our first reference in this regard, and though it heavily favors machines with an SSD, that’s not necessarily a bad thing, as machines with SSDs really do feel that much faster than most which lack that trait.  Here, the X240 scores nearly identically to both the T440s and the Flex 14, which seems to suggest that (since the T440s and Flex 14 share the same oddly subpar SSD), the benefits of a fast storage device eventually diminish beyond recognition in the benchmark’s eyes.  We’re also content not to argue with that interpretation, as to be honest, we can’t tell much of a performance difference between any of the three machines.  That is to say, they all feel fast.

February 25, 2014 | 10:57 AM - Posted by Graham L (not verified)

I have been a Thinkpad fan for many years. I've purchased a lot of Thinkpads in both the X and T series.

But I can't say that I'm a fan of what they did to the X-Series. The exlusion of a tablet edition of this laptop is very frustrating. And with a promised 1080p screen that seems to be some kind of Unicorn model, I don't really understand why this would be appealing over the T440s. Sure the size is smaller, but the weight difference isn't much, and the performance on the T440s is better.

I also don't like the soldered on DIMM fused with a single DIMM slot, this makes Dual Channel memory difficult to accomplish and a 12 GB cap on memory is kind of lame with the previous model could go up to 16 GB. Also the Previous model could get long batter life with the addition of a slice battery, sure it was extra weight, but I didn't have to compromise on memory, or loss of usb port.

February 25, 2014 | 01:14 PM - Posted by Anonymous (not verified)

I'm liking my decision (X230 with Windows 7) better every day.

February 25, 2014 | 09:08 PM - Posted by John Foster (not verified)

Knowing there would be an X240 along within a year I pondered long and hard whether to buy an X230, but I did, summer 2013. I'm glad I didn't wait for this model. Looks like Lenovo are selling out on their previous culture of loading a small laptop with top quality components in a strong and desirable frame. Yes it's only a marginal deviation from the past but it's the thin edge of the wedge.

Looks like the X230 is the last of Lenovo's high quality 12.5" laptops.

The X230's chicklet keyboard is wonderful.

February 26, 2014 | 02:59 AM - Posted by Anonymous (not verified)

Sadly, we have reached the end of usable keyboard layouts on notebooks, following the lack of quality high-res 16x10 displays. Such a shame.

No Insert key. (Seriously? Fn+I?)
Other keys, like SysRq, are also magic sequences.
Broken Fn/Ctrl, and different sizes so they aren't physically swappable after changing the firmware setting.
Page Up/Page Down is in the wrong place. (I have used it every day for the last 9 months and still can't really get used to it.)
WTF is with a dedicated large print screen button?
And WTF is with this new mouse crap? It's why I didn't wait for a W540.

People were crying about the chiclet keyboard in the past, but that isn't the problem (I use a W530 and x120e daily and the feel is fine). The problem is the inane locations of buttons and how they deviate so much from model to model now. I wasn't a big fan of the previous IBM/Lenovo keyboard layouts but they were consistent and I could live with and adjust to them. With the new models though, the inconsistencies continue to grow, and some things are just retarded - like no space between function key groups on the W530 (that's about the one thing the X240 gets right...). And I can't edit code on my W530 then tweak it on my X120 without problems as ins/del and home/end are mixed up, for example... and the X240 doesn't even have Insert!

Dell decided to ruin keyboard layouts about 3 years ago, and in the last year Lenovo has fallen in line.

With the X240, we now see the immediate future. And this future shows that there are no longer _any_ notebooks on the market at any price with usable screens and usable keyboard layouts.

February 26, 2014 | 03:00 AM - Posted by mathew7 (not verified)

Reading the review, I kept feeling better and better over my x230 aquisition in november. I saw then the official pictures of x240 in the lenovo psref pdf and I hated the hinges since you lose back space (also on a cluttered desk, you need extra space for the screen).
I guess I'm gonna use it a long time from now. I am very conservative on laptop designs, and Lenovo/IBM kept their designs the longest (ok...I may be biased...but every time I looked at other brands, I kept getting back to Lenovo designs).

February 26, 2014 | 07:55 AM - Posted by Pes5 (not verified)

I have been using ThinkPads since mid-90s, and my current X230 is most likely the last one to be sort of happy with. I cannot accept loosing the dedicated F-keys. I am barly accepting changes in pgup and pgdn keys... It is all against productivity users that prefered their hands on the keyboard, and using the red stick..Yes, Lenovo ruins Thinkpads and this is very sad.

February 26, 2014 | 04:21 PM - Posted by waffle (not verified)

Agreed, this is sad.

February 27, 2014 | 08:56 AM - Posted by Steve (not verified)

The review doesn't mention the msata capabilities. Can it take the standard 50mm cards or is it stuck with the 40mm? Being able to accept industry standard msata in the msata port is vital. Thank you.

March 21, 2014 | 01:51 AM - Posted by Anonymous (not verified)


March 3, 2014 | 11:08 AM - Posted by Anonymous (not verified)

X220 is still the best.

May 13, 2014 | 05:02 AM - Posted by TechSolvers (not verified)

For anybody needing help with changing the keyboard in this model, you can find a full tutorial here:

November 5, 2014 | 06:58 AM - Posted by David (not verified)

i have an x240 and want to use the SIM slot so i can browse but after inserting the SIM card nothing happens. how do i get it to work. Please Help

December 25, 2014 | 12:10 PM - Posted by Delboy (not verified)

I don't know where all these complaints come from, but for me having just bought the X240, it looks like the ultimate workhorse, a badass road warrior. I can maybe understand the keyboard complaints and I know some people are all about the processing power, BUT, keyboards are something you can get used to and unless you want games, you really don't need anything more than a core 2 duo on a 12.5 inch ultraportable. For me it all comes down to battery life! And mil-spec durability, in a backpack size laptop of less than 2 kg! I often have to be in places with bad conditions and no charging sockets available, or have to spend 5-10 hrs of travel for an event and back again all on one charge. If you really want a sleek, fast and sexy machine buy a Macbook Air. If you want a machine that will do the job on the go under any conditions look no further. Oh, and did I mention the native support for Linux?

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