Lenovo Thinkpad Twist Convertible Ultrabook Review
System Display, Audio-Visual, Cooler, and Battery Life Testing
To validate the quality of the system's display, view angle tests and monitor calibration tests were performed. The view angle tests were done by taking a picture of the display with the PC Perspective site active from a 30 degree angle from the plane of the display. For the monitor calibration tests, the Lagom LCD monitor test pages were used.
View Angle Testing
As you can see from the screen shot, the display viewing angle is surprising good from the side of the monitor. The site colors remain vibrant and the text is clear and readable. Two factors come into play here for this amazing feat - the IPS LED display itself and the Corning Gorilla Glass overlay. IPS LED back-lit displays are well known for their quality and crispness and are highly sought after. Add the Gorilla Glass coating and you have the enhanced viewing angle clarity that we see with the Thinkpad Twist's display.
Monitor Calibration Testing
The monitor calibration tests further proved the quality of the display Lenovo chose to design into the Thinkpad Twist. Both the Black level and White saturation test screens were spot on, meaning that the display showed both black and white colors accurately. In the Gradient testing, only minimal banding was apparent in the test patterns which again illustrates the quality of the monitor. Further, the monitor showed no flicker at all when the Inversion test page displayed.
The system's audio-visual subsystems were tested through record and playback means were applicable. For testing of the embedded microphone and webcam, a test video was recorded at a resolution of 720p using a Windows-based video recording application. For testing the in-built stereo speakers, selected audio tracks were played back using Windows Media Player.
The recorded video playback was without issue for the most part with both the audio and video captured accurately during the recording. The video playback did appear to studder a minimal amount most likely due to the raw format of the recorded video stream. This stuttering was not seen during playback of encoded movies at 720p. The audio quality in the video was good as well with no distortion encountered.
Audio Playback Testing
Unfortunately, the music playback did not fair as well as the video playback. The audio quality for true stereo music was sub-par, even though playback was distortion-free. The audio came through without much in terms of base with the resulting audio sounding very tinny and muted. This lack of audio quality stemmed from the placement of the Thinkpad Twist's speakers underneath the keyboard assembly. This layer on top of the speakers is the one design flaw in an otherwise great product.
System Cooler Testing
To best gage the quality of the system cooler, system temperate and audio measurements were taken with the system idle and under load. To replicate a normal system load, the Unigine Heaven DX11 Benchmark v3.0 was run repeatedly over a 10 minute period with the ultrabook placed on a flat, non-porous surface. Temperature measurements were taken from three areas on the ultrabook for each test phase - the center of the display, the center of the keyboard, and at the CPU vents from the underside of the system. Temperature was measured using an infrared based hand-held thermometer unit. Sound measurements of the system cooler where taken with the sound meter placed 1 foot away from the ultrabook with all other devices in the room silenced. The Sound Meter Pro applet on a Samsung Galaxy S3 mobile phone was used to measure decibel level.
As you can see from the temperature tests, the Thinkpad Twist at idle remains at a cool 33C even on a non-porous desktop surface. Under load, the hottest point on the device gets to a manageable 49C while resting on a desktop. At idle, the built in cooling fan is barely audible at 32dB, while getting just a bit louder while under load and sitting on a desktop surface at 37db. The cooler noise becomes apparent if the ultrabook bottom is lifted off the desktop increasing to 46dB. The increase in fan noise has to do with more airflow getting to through the bottom air vents when the ultrabook is not resting on a solid surface.
System Battery Testing
The system battery life was tested during both discharge and charge cycle to give you a better idea of what to expect during normal and extreme use of the ultrabook. Three different battery benchmark programs were used to gage battery life - Battery Eater Pro, the PC Perspective Battery Test, and the FurtureMark Peacekeeper battery test. Battery Eater Pro renders a rotating image at 1024x768 stressing the CPU and graphic components of the laptop. The PC Perspective Battery Test steps through a series of web pages using the Firefox browser. The FurtureMark Peacekeeper battery test runs through a series of HTML 5-based web pages using the Firefox browser. In all cases, the test runs until the device's battery is depleted.
For these tests, the system power settings were set to the High Performance mode in the Power Options control panel. This power plan was modified while in battery mode as follows: display set to not dim, turn off or sleep, screen brightness set to 80%, processor minimum state set to 100%, and critical battery level set to 1%.
The battery test varied, but did not come close to the promised 7+ hour lifespan from the Lenovo device specs. Both of the normal use tests (the PC Perspective and Peacekeeper site crawls) came in with either just under or just over 3 hours of battery life. The Battery Eater test drained the Thinkpad Twist in about 1 hour and 20 minutes. However, the Twist was found to fully recharge in about 1 hour and 45 minutes. Not great when compared to the advertised battery life, but not too bad considering the powerhouse sitting under the Twist's hood either.