The Kaby Lake Refresh series (also called 8th generation Core-i) is a new series of ULV quad-core processors. These chips were first made available in consumer laptops last fall, and business devices are now following suit. We are currently testing many new Lenovo ThinkPads that are all equipped with the 8th-generation quad-core processors.

So far, so good. But there are big differences in performance between these devices. In general, the new quad-core ULVs, like last year's dual-core ULVs, have a TDP of 15 watts, which means that the processor is allowed to consume 15 watts. Under load, this is only enough power for 2.2 - 2.4 GHz (this varies a little depending on the chip). This is above the usual base clock rates, but far from the high Turbo Boost results that would offer great performance. The "small" Core i5-8250U, for example, would need more than 30 watts to reach the full 4x 3.4 GHz - twice as much as its actual TDP. The full 3.7 GHz with the i7-8550U require over 40 watts.

We have taken a look at the new Lenovo ThinkPads and measured how much performance is available for a short time, and under continuous load. In order to do so, we have used the Cinebench R15 Multi test, which we ran in a loop for 50 times. We will update this list with further test results for new models as soon as they are available.

