Kısa inceleme: Lenovo ThinkPad T570 (Core i7, 4K, 940MX) Laptop

One of the main attractions of our better-equipped T570 model is surely the built-in UHD IPS display (3840x2160). Among other things, this is also because Lenovo's other display options are semi-great at most. As customary for business laptops, there is an HD TN option (1366x768), which the buyers should definitely avoid. The display option that is built into most of the T570 units is the Full HD IPS (1920x1080) display, which we evaluated in our first test. That display was not quite able to convince us: Although, as is typical for IPS displays, the viewing angles and the contrast are good, the comparatively low brightness of 245 cd/m² and the very low color space coverage left much to be desired. We already knew that from the predecessor, the T560. The old curse that business devices have displays that are rather below average, has not been completely overcome yet.

On the basis of the measurements of the 4K/UHD display, we can say with a clear conscience that at least in the most expensive display option, Lenovo has done almost everything right. It was also true in the T560, whose 3K IPS display option (2880x1620) is replaced by the 4K display (the T570 is the first ThinkPad of the T-series with a 4K display ever). Just the display brightness is reason enough to reach for the expensive display option. At 314 cd/m² on average, the built-in panel coming from BOE is considerably brighter than the Full HD display. With this, the 4K display does almost as well as the 3K display in the predecessor: a good result, even if the displays in the Dell XPS 15 and especially in the Apple MacBook Pro 15 are again much brighter than that. As with the 3K predecessor, the 4K panel has some PWM, although it is with a much higher frequency of 925 Hz, which should give no cause for concern to most users. The display hardly shows any backlight bleeding; only during bootup it can be seen minimally on the bottom edge. At 89% the brightness distribution is good, but not outstanding. Shadowing cannot be seen with the naked eye.

At the first glance, you might think that Lenovo has left everything as is in the dedicated graphics chip, since the T560 predecessor was already equipped with the GeForce 940MX. However, this year Lenovo has finally made use of the 940MX's advantage over the direct 940M predecessor, using GDDR5 instead of DDR3 storage. Otherwise, not much changed with the chip; it is still a GPU of the lower mid-range which uses the outdated Maxwell architecture. A successor based on the Pascal architecture is not yet in sight.

The move to GDDR5 pays off: compared to the predecessor, the T570 is clearly more or less faster, depending on the benchmark. In the 3DMark Cloud Gate benchmark where the T570 is ahead of the T560 by 34%, the difference is particularly large, but also in the Fire Strike benchmark, it can clearly move ahead by an increase of 28%. The older 3DMark11 results in a smaller increase of 16%, however. Despite this performance improvement, it is still far behind the Pascal-based GeForce GTX 1050, which is built into the Dell XPS 15. 

Unlike the CPU, the Nvidia GPU is not throttled during battery operation and its full power remains available. This is an important difference compared with the T570 without dGPU, since there, the integrated Intel HD Graphics 620 GPU was affected by performance throttling like the CPU. By the way, the Intel HD 620 is losing in the benchmarks to the GeForce 940MX in the T570 by about 47 to 64%, depending on the test.

While idling, the fan is turned off permanently, as it should be for a 15.6-inch notebook with an energy saving ULV processor. During everyday operation, the test unit remains quiet as well, at least as far as the fan is concerned. If you hold your ear closer to the keyboard, a sort of hiss becomes audible near the TrackPoint. Not good for something like this to occur in a device of this price range.

During load, the fan turns on and can be clearly heard at a maximum of 41.3 dB(A), although the whirring of the fan does not have a frequency that feels uncomfortable. Also, it is not so loud as to become a massive disturbance.

As expected, in the model with dGPU, Lenovo uses a cooling system that is slightly stronger. The biggest difference is having two copper heat pipes, instead of just one. 

While idling, the T570 with dGPU remains cool and quiet. Not surprising, since thanks to Optimus, the dedicated GPU is deactivated during idle mode, so there is no difference here. Under load, however, the difference is dramatic: Particularly on the bottom, the T570 becomes very hot, and the 60 °C mark (140 °F) is crossed at the hot spot in the center of the bottom. This makes using it on your lap impossible under load. At least the hand rest warms up only moderately, preventing the T570 from becoming too hot to be usable. Undoubtedly, this is a negative point. 

Despite the high surface temperatures, the T570 with the GeForce GPU does not entirely come off badly. As in the test unit without dGPU, the TDP increase to 25 watts in the stress test remains without effect: after several seconds with the full Turbo, the clock drops to around 2.2 GHz, varying significantly, sometimes even dropping down to 1.8 GHz. After about 5 minutes, the clock speed stabilizes above the 2 GHz mark, at times reaching 2.8 GHz, staying at 2.6 GHz on average. Thus we have throttling, but it is not dramatic. This is caused by the temperature as well as the TDP: the TDP of the CPU is at around 12 watts during the stress test; in addition, Lenovo sets a temperature limit of 75 °C (167 °F), which was only crossed minimally in the test. The GPU can maintain its maximum clock speed of 1150 MHz for a long time, but after about 20 minutes, the clock speed falls to 980 MHz.

A 3DMark11 benchmark run right after the stress test was unremarkable, so in everyday use, the throttling problems remain within limits.

The more expensive T570 can convince us just as much as the more affordable model. It has many good characteristics that our initial test unit also had: the robust, relatively compact case, the comfortable input devices, as well as the many connection options. Practical features such as PowerBridge or the infrared camera turn the T570 into a very flexible laptop. In addition to the advantages from the affordable T570, now also come the 4K display of a convincing quality and the NVIDIA GPU, which, despite being an older model, is considerably more powerful than the Intel GPU integrated into the CPU.

However, this model is also not without problems. Our biggest complaint is the enforced CPU performance reduction during battery operation. During mains operation, we could avoid the performance fluctuations in this model with a settings change, but the performance during battery operation cannot be raised in this way. An added, new problem is the heat development on the bottom during load, which can probably be attributed to the Nvidia GPU. In terms of this problem, the T560 did a little better, perhaps due to its thicker and larger case. In addition, the price for the non-student version of the T570 with 4K display and Nvidia GPU is not really very affordable, and the supplied power supply is not sufficiently sized for operation during load.

With the 4K display, the T570 presents a good overall package and is a promising candidate in the 15.6-inch segment, since it offers an interesting combination of business features and multimedia characteristics.

In summary, the T570 with a 4K display can be clearly recommended. With this display, it was markedly improved in a crucial area where the initial test unit had disappointed. If it were not for the performance reduction during battery operation, it would have achieved a "very good" recommendation. Here we reduce the end note by two percentage points. With this, the reduction is slightly less than for the first test unit, since at this time, the GPU is not affected by the performance reduction and the performance in mains operation is stable.

There are countless alternatives with a 15.6-inch display, whereas the business sector in particular is more concentrated on the 14-inch format. The MacBook Pro 15 and the Dell XPS 15 are strong competitors, which do not offer the business features and the excellent keyboard of the T570, but considerably stronger GPU and CPU options, instead.