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Review Asus VivoBook U38DT Subnotebook and battery life

The VivoBook U38DT-R3001H is for mobile users who need a compact, lightweight and portable device. Under the hood of the aluminum chassis is primarily AMD hardware.

ASUS A85D Battery Let us start with a few specs before we get to the details: Asus has decided to use the A8-4555M CPU. The inexpensive ULV model is primarily focused on newcomer and modest users with a clock of 1.6 up to 2.4 GHz. The dedicated graphics card performs better. Depending on the application the performance of the Radeon HD 8550M is in the low or mainstream area. ASUS A85DE Charger

The memory equipment is midrange with 4 GB DDR3 RAM (1600 MHz). While 2 GB are in a common slot, the remaining two GB are soldered onto the mainboard. To avoid storage problems Asus integrates a 500 GB hard drive with 5,400 rpm. The anti-glare display with a resolution of 1366x768 is suitable for the notebook class. The operating system is Windows 8 64-bit. ASUS A85DR Battery

The excellent case is one of the great strengths of the VivoBook U38DT. Asus almost exclusively uses brushed aluminum that gives the 13-inch device a great quality impression. The silver-gray colored surfaces are exceptionally sophisticated. Except for the manufacturer labels (cover & display frame) the 13-inch device is matte finished throughout. Very few notebooks are that dirt resistant. Compared to other devices the surfaces are pretty durable. ASUS A85N Battery

The praise continues with the good stability: Despite the thin case the surfaces hardly dent even under high pressure. Smaller weaknesses can be found with the touchpad and in the center of the keyboard. The subnotebook also offers a great performance when it comes to the looks. University, office or desk at home: The 13-inch device looks good in every environment. ASUS A85V Battery

Because of the low height (just under two centimeters [~0.79 inches] at the thickest point) and the lightweight construction (1.55 kg/~3.42 pounds) the mobility of the device is very good. Standard notebooks appear enormous and bulky next to the U38DT. Even the light (236 grams/~0.52 pounds) 65 Watt power supply unit is directly connected to the socket and at 75 x 75 x 28 millimeters (~2.95 x 2.95 x 1.10 inches) also surprisingly small. ASUS A85VD Battery If you are often on the road you do not want to be without it. Thanks to the small dimensions the subnotebooks becomes the ideal companion.

In the category of build quality the manufacturer does not disappoint as well. The material transitions of our review sample were very clean. The hinges are also well designed. The base unit does not swing: the device can be opened with one hand. Great: Vibrations have almost no impact on the cover. ASUS A85VJ Battery

Maintenance
A special tool is required to access the inside of the subnotebook. The reason is that the bottom cover is made of a single metal plate and attached to the case with 12 Torx screws. The absence of a typical maintenance cover, which allows fast access to the memory and hard drive, might have a negative impact for some users. To avoid damage to the shop unit we did not remove the bottom cover as an exception. ASUS A85VM Charger

The amount of preinstalled software is small: 25 applications are an indication of a reasonably cleaned up hard drive. In the windows control panel (right picture) the buyer discovers primarily drivers and manufacturer tools. Numerous elements are already known from other Asus notebooks. The "Splendid technology", for example, tunes the color reproduction. ASUS A85VS Battery "Power4Gear Hybrid" handles the energy settings. The "USB Charger Plus" supports the charging of external USB devices.

Accessories
The scope of delivery is pretty standard. Additional to the port adapters are; a warranty card, a manual and zip ties. Absolute highlight is the brown colored and pretty tight notebook bag. The leather cover is attached to the textured main body via Velcro. The black inside provides a good basic protection. Driver and Windows DVDs are not included. For the system recovery you can use the Windows function Restore (PC settings, general). ASUS F45 Battery

Input Devices

Keyboard
The dark gray chiclet keyboard leaves a good impression. Thanks to generous key lettering and the white illumination, which can be adjusted in multiple steps, the result is a very convenient input. Typical for Asus is the uneven illumination, but is has almost no negative impact for everyday use. ASUS F45A Battery

The key size (mainly 16 x 14 millimeters/~0.63 x 0.55 inches) should also be convenient for most users. Be aware the arrow keys and the keys of the F-row are pretty small (only 8 millimeters/~0.31 inches high). The layout is okay, yet the combined Ins/Del key was distracting. There is not much to complain about with the keyboard feeling: pressure point and stroke are designed sufficiently. ASUS F45C Battery Nice details like the slightly rounded edges are other factors for the positive overall picture. With our experiences the keyboard is suitable for frequent writers.

As usual, with Fn-combinations several comfort functions can be activated. Besides the brightness the volume can also be adjusted. A deactivation/activation of the wireless module, the display and the touchpad is also possible.

Touchpad
The minimally lowered touchpad is strikingly similar to the mouse replacement of the recently reviewed Lenovo IdeaPad Y500. Similarities do not only come with the dimensions (10.5 x 7.0 centimeters/~4.13 x 2.76 inches) but also with the buttons. ASUS F45U Battery The latter are directly integrated into the smooth touchpad surface.

The corresponding mechanisms are definitely a matter of taste. While one appreciates the seamless transition to the button area, the other criticizes the limited stability. Compared to the Lenovo IdeaPad Y500 the touchpad cannot be pushed in so deeply but the stability is not quite perfect. The convenient gestures that are presented clearly in the Smart Gesture software (see screenshot above) also have their flaws. ASUS F45V Battery The zoom function is especially unruly.

Although the precision is at a decent level, Asus could put some work into the accuracy of the touchpad. All in all it is still enough for the rating "Good".

The 1.6 to 2.4 GHz clocked A8-4555M belongs to the family of power efficient ULV processors and is produced, like its Trinity siblings, in the outdated 32 nm process (Intel is long producing in the 22 nm process). With 19 Watts the Thermal Design Power is significantly reduced compared to the standard models. ASUS F45VD Battery The similar clocked quad-core A8-3500M (1.5-2.4 GHz), for example, has almost twice the TPD with 35 Watts.

The A8-3555M can only process one thread per core simultaneously because of the lack of Hyperthreading or similar parallelization technology. Four MB L2 cache seem pretty much compared to Intel products, however the Core-i generation also has a 3 to 8 MB large L3 cache. The immediate Intel competitors Core i5-2537M (1.4-2.3 GHz) and Core i5-2467M (1.6-2.3 GHz) cannot compete with 1.3 billion transistors.ASUS F45VD1 Battery Both Sandy-Bridge representatives "only" have 624 million transistors.

Throttling
The manufacturer has a big problem with the processor. When more than one core is in use, the clock of the A8-4555M is temporarily reduced from the standard 1.6 GHz to a meager 900 MHz. Our measurements show that the throttling can have a massive impact on the performance. We checked the energy settings repeatedly (Windows control panel and AMD drivers) and the results with the second review unit were too low as well. ASUS F55 Battery We assume a general problem with the VivoBook U38DT.

During use of a single-core the situation is more relaxed. According to the tool CPU-Z the A8-4555M does not come close to the maximum available turbo clock, but at least it is 200 MHz more than the base clock with 1.8 GHz.
CPU Performance
The low CPU performance is the weakest point of the subnotebook. The Cinebench R11.5 score is very low with 0.42 points for the single-core rendering and 0.78 points for multi-core rendering. ASUS F55A Battery The already mentioned Core i5-2537M is more than 100% faster with 0.9 and 1.93 points (Samsung Series 5 530U4C-S02). Even the slow 1.4 GHz Core i3-2367M with 0.53 and 1.32 points is superior (Asus UX32A-R3001V).

If we have a look at the Lenovo IdeaPad S405 we can see that the A8-4555M without throttling and a higher turbo margin achieves 0.57 points (+36%) and 1.24 points (+59%). ASUS F55C Battery We can only hope Asus fixes the problem with the clocks as soon as possible.

GPU Performance
The performance of the AMD graphics very much depends on the requirements of the application being used. The higher the CPU influence, the higher is the limiting factor of the throttling A8-4555M.

The subnotebook handles the 3DMark 11 (1280x720, "Performance Preset") quite well. With a GPU score of 1,307 points the Radeon HD 8550M is on the same level as the GeForce GT 640M LE (1,259 points @ Fujitsu LifeBook AH532) or Radeon HD 7690M XT (1,346 points @ HP Pavilion dv7-6c07eg). For comparison: The Radeon HD 7600G only manages half of that (628 points @ Lenovo IdeaPad S405). ASUS F55CR Battery

The result of the Unigine-Heaven-2.1 benchmark (1280 x 1024, High, Tessellation normal) is not very overwhelming. With 14.1 fps it can compete with the GeForce GT 630M at most (14.3 fps @ Medion Akoya P6633).

System Performance
Because of the second-class hard drive and the pretty slow CPU the performance of the overall system is in the bottom third. 1,714 points for the PCMark 7 won't impress anybody. With this result the 13-inch device can only compete against notebooks with a cheap Intel B-series processor (Pentium B950 to B980). ASUS F55U Charger Among others we have the Lenovo IdeaPad G580-MBBG3GE (1,670 points), the HP Compaq Presario CQ58-148SG (1,700 points), the HP Pavilion g6-2200sg (1,723 points) or the Lenovo IdeaPad N581-MBA4YGE (1,742 points).
Gamers should avoid the VivoBook U38DT. The low clock of the A8-4555M pulls the performance down to a level that only modest and/or older games can be played with more than 25 fps. From the 25 tested titles only 10 were fairly playable. ASUS F55V Battery Most of the time the user has to live with minimum details and a slightly reduced resolution.

And even if the frame rate suggests a smooth experience on paper, during gaming there are constantly annoying frame drops due to reloading - whatever settings you select. Even the integrated Intel HD 4000 processor graphics performs better sometimes. Without the CPU throttling the performance should be much better. ASUS F55VD Battery

System Noise
While idling the noise level is similar to the Asus UX32A-R3001V (Core i3-2637M & HD Graphics 3000) we reviewed a few months ago. Just under 31 dB (A) is quite low, although the 13-inch device is never completely silent. Even with little load the user hears a slight noise and a subtle clatter of the hard drive. Simple tasks like MS Office, video or web browsing are also not disturbed by a distracting noise level. ASUS F55VDR adapter

With CPU-intensive tasks (3D applications etc.) the sound intensity rises to a proper but not annoying level. From a distance of 15 centimeters (~6 inches) we measured an average 38 dB (A) for the 3DMark 06. Although the fan noise is pretty high-pitched (and makes the notebook subjectively louder than the values would suggest) it can be tolerated pretty well. ASUS F75 Battery More than 41 dB (A) were not possible even in our stress test. The identically priced UX32A (800 Euros/~$1092) has no dedicated graphics and is quieter under load (36-38 dB (A)).
The temperature development was good without exceptions. During idle the whole chassis remained pleasantly cool: Just under 27 °C (80.6 °F) provides convenient long-term use. At higher loads the rear area of the notebook gets noticeably warmer. ASUS F75A Battery A maximum of 43 °C (109.4 °F at the top) or 38 °C (100.4 °F at the bottom) are non-problematic. The palm rest reaches a maximum value of 31 °C (87.8 °F) - a moderate result.

Overheating of the hardware is no problem. After one hour maximum load (FurMark + Prime95) the graphics and the processor remain at around 80 °C (176 °F).

Energy Consumption
The switchable graphics make sure the 13-inch device wastes no unnecessary power. With 10 to 17 Watts the consumption during idle is slightly above the Asus UX32VD with a 1.7 GHz Core i5-3317U and a GeForce GT 620M (6-13 Watts). ASUS F75A1 Battery Under load the VivoBook U38DT is more frugal (42-52 Watts against 45-61 Watts).

Battery Runtime
The non-removable battery has a capacity of only 48 Wh and the runtimes are very limited. Under load and with maximum brightness the battery keeps the device running for 1.5 hours, with wireless Internet browsing and medium brightness just under 4 hours are possible. The result of the idle test is not listed because of some strange values (Battery Eater seems to be always assigned to the Radeon HD 8550M). ASUS F75V adapter A DVD test was not performed due to the lack of an optical drive.

If you overlook the limited port equipment and the annoying throttling (multi-tasking reduces the CPU clock to 900 MHz), Asus made almost everything right with the U38DT-R3001H.

The main attraction is the very stylish and very lightweight metal case (only 1.55 kg/~3.42 pounds). Such a high build quality usually cannot be found in devices less than 1000 Euros (~$1365). Apart from some small details the input devices are also very good. ASUS F75VD Battery The manufacturer shows no weakness with the display either. The matte HD panel offers decent to good values.

Considering the low notebook height (less than two centimeters/~0.79 inches) we find the performance reasonable. Further positive aspects are the moderate temperature and noise levels. Even under heavy load the 13-inch device does not get excessively loud or warm. The included notebook bag helps to overlook the missing driver and recovery DVDs. ASUS F75VD1 Charger The battery runtime could have been better for our taste. Runtimes over 4 hours are only possible with little load and reduced brightness.

All in all we can still give a clear buy recommendation for the U38DT-R3001H. Price conscious users who want a small device with high mobility are at the right place.