Performance – Processor, Applications, Storage Devices

At least on paper, the ThinkPad Yoga ought to coast through most typical business challenges in much the same way as did the X240 and T440s (not to mention the IdeaPad Flex 14 before them).  A couple notes to help differentiate it from those recent challengers: firstly, all three of those previous models featured the i5-4200U, which is a small step down from the i5-4300U: it carries a lower clock rate (1.6 – 2.6 GHz under max Turbo Boost, 2.3 GHz for 2 active cores; the i5-4300U boosts all of those values by 300 MHz) and a slightly lower GPU clock rate (1000 MHz vs. 1100 MHz on the i5-4300U).

Secondarily, the 4 GB of RAM in our ThinkPad Yoga is—interestingly enough—the first dual-channel RAM configuration we’ve seen in any of these models.  That makes a notable difference in terms of system performance and provides a significant performance boost in the realm of integrated graphics via the Intel HD Graphics 4400 adapter.  We should thus expect to see improved performance on all of these fronts if all other factors are held equal (throttling tendency, Turbo Boost capability, storage device performance, etc.).

Performance – Stress Test

As always, we employ FurMark for our CPU and GPU stress testing, to help synthesize full-load conditions and allow us to monitor temperatures and clock rates as the notebook seeks to cope with them.

Under full CPU load (using FurMark’s built-in CPU Burner), the ThinkPad Yoga quickly reveals its inability to handle heavy-duty operations.  In spite of its higher ceiling for Turbo clock rates, frequencies only began at the 2.6 GHz level before quickly dropping to 2.3/2.4 GHz once temperatures reached the 60°C mark.  This is still pretty good, especially considering that the overall maximum temperature only reached 73°C, but it doesn’t bode well for our coming GPU and combined stress tests, and it serves as a premonition for reduced performance premiums in our benchmarks as well.

Sure enough, our GPU fears were quickly corroborated by the FurMark GPU stress test.  Though the Turbo Boost maximum for the i5-4300U integrated GPU (Intel HD Graphics 4400) is 1100 MHz, the ThinkPad Yoga only ever reached a stable 599 – 649 MHz in practice thanks to temperatures quickly rising to the 85—90°C range (the overall maximum we encountered was 90°C).  Likewise with the combined CPU/GPU stress test, where we saw the CPU sitting permanently at a throttled clock rate of 800 MHz and the GPU struggling to make ends meet at a middling 499 – 549 MHz.

In short, don’t expect record-breaking performance from this convertible.  The cooling system is simply too low-key to allow for proper performance gains under heavy use. MHz.

he GPU struggling to make ends meet at a middling 499 – 549 e CPU sitting permanently at a throttled clock rate of 800 MHz

Performance – Processor

The i5-4300U might not be a powerhouse CPU (after all, it carries only a 15W TDP), but it’s one of the most popular inclusions in modern Ultrabooks, and for good reason: it offers a valuable trade-off between performance (with the ability to Turbo Boost up to 2.9 GHz single-core and 2.6 GHz dual-core operation provided thermal headroom exists) and power consumption.  Its TDP is just 2 W above that of the Yoga 11S’ Core i5-3339Y, and yet the 3339Y’s max turbo clock rates are 2.0 GHz (1xCPU) and 1.8 GHz (2xCPU) respectively.  That’s a pretty remarkable difference given the small jump in power consumption, and it’s part of what makes Haswell so useful for mobile chipsets.

But we won’t know how well this actually factors into real-world performance without subjecting the machine to our usual barrage of performance tests.  So let’s get started!

SiSoft Sandra Processor Benchmark

In spite of the throttled CPU performance under load (which the T440s did not experience in our testing), we still find improved Sandra Processor Benchmarks results on the ThinkPad Yoga, which is encouraging.  In fact, we measured 12% and 26% gains over the T440s (the closest competitor with the same chipset) in Whetstone and Dhrystone respectively, which is well in excess of what we would have otherwise expected based on specifications.  It also absolutely destroys the 13 W TDP i5-3339Y of the Yoga 11S.  By comparison, 2012’s ThinkPad X230, which featured a 35W TDP with a maximum Turbo clock speed of 3.3 GHz / 3.1 GHz (single-/multi-core) still wins out by a 20%/9% margin in these same tests—but, of course, at the expense of 20 W additional maximal power consumption, which is 133% more than the i5-4300U to help put it into perspective.

Cinebench R11.5

In Cinebench, the ThinkPad Yoga is once again the best of the Haswell low-voltage models, besting the second-place IdeaPad Flex 14 by 10.5% and 3.6% in multi-/single-CPU operation respectively.  The Yoga 11S is once again far behind here, with scores 45.5% and 57.5% lower.  Again, that’s a massive sacrifice for just 2 W TDP—especially when you consider that our battery test results (and the weight of the system) haven’t changed much.

General System Performance

So, what about overall system performance, as a precursor to our storage benchmarks?  We use PCMark 7 to help assess this.

PCMark 7

Hey now—with a 4942, the ThinkPad Yoga is the new king of the Lenovo Ultrabooks, including the T440s and the X240.  It’s a great result overall and is certainly due in part to the very fast SSD, which we’ll examine next in more detail.

Performance – Storage Devices

The SSD in the ThinkPad Yoga is identical to that of the ThinkPad X240; it’s a Samsung 256 GB model MZ7TD256HAFV-000L9, a.k.a. a Samsung 840 Pro series drive, which is still one of the best on the market in terms of performance.  Let’s see how it fares:


Our AS SSD results favor the X240 in this case, though the difference is only in the realm of read speed (write speed on the Yoga was actually better).  The T440s’ 840 Pro 128 GB model was somewhat slower on reads and considerably slower on writes, which is to be expected from that particular drive model (which features oddly limited write performance as compared to its 256 GB sibling).

ATTO Disk Benchmarks

Things match up a lot more consistently in ATTO, which helps to suggest that our AS SSD results may have been an exception due to some sort of extraneous factor.  Performance between the X240 and ThinkPad Yoga is identical as expected; the T440s, again, comes in at around half the write speed.  Looking further down the list to the Yoga 11S we find identical speeds until the block size is reduced to 4KB, where the Yoga 11S’ PM841 256 GB chokes, churning out speeds 80% and 59% slower in read/write respectively.  Still, the Yoga 11S’ write speed beats the T440s’ drive by nearly 22%.

CrystalDiskMark 3.0

The HD Tune results speak for themselves; the drive in the Yoga is all round quite fast, especially in terms of read speeds.  The 4K write performance is also good.

HD Tune

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