ASUS U3S: Two Notebooks in a Single Case

The U3S is an expensive product that delivers good performance and features broad functionality. From a technical standpoint, the U3S is a well-balanced solution in terms of weight, size, and power consumption. It is not a cheap buy, yet it won’t disappoint you if you choose it. Read more in our review!

by Alexander Britvin
03/16/2008 | 10:26 AM

Talking about a good notebook, we mean a light notebook so that it could be easily carried in a bag on your shoulder, an economical notebook so that it could work for a few hours on its battery, and a top-performance notebook so that you could play your favorite game on it at home. Alas, these notebooks cannot be one and the same model because it is virtually impossible to meet all these requirements in a single machine. Most manufacturers offer at least two distinct series: you can have either a lightweight and economical or a top-performance notebook.


This classification is acceptable for a majority of users, though. If the notebook is bought as a replacement of a desktop PC, its mass, weight and battery life don’t matter much. And if you are going to use it as a traveling assistant, you want it to run office applications that don’t require high performance from the CPU or the graphics card.

But what if you cannot choose between these two product classes? Do you have to buy two notebooks or give up some of your requirements? The solution was found a year ago by Sony’s engineers and implemented in the SZ series: the notebook had two graphics cores, one with low performance but also with low power consumption, and the other with high performance. This solution looks obvious because a top-performance GPU is one of the hungriest consumers in a modern computer and power-saving technologies help but little with that. On the other hand, it is a daunting engineering task to accommodate two video outputs and the logic to select what output the display is connected to within the limited dimensions of a notebook’s body.

Anyway, this solution seems to have been accepted by the manufacturers. And today we are offering you a review of the ASUS U3S notebook that features two graphics cores, too.

The letter U in the product name indicates a product from the Superior Mobility series like the recently reviewed U1F. The U3S is more advanced and larger, though. Besides the two graphics cores (you can choose the core to use by means of a slider switch on the right panel), the notebook features Intel’s Santa Rosa platform with a Merom-core Core 2 Duo processor. The notebook may be optionally equipped with a 3G module, a GPS module (it is present in our sample), and an Intel Turbo Memory module. You can’t have all the three modules at once, however, because the mainboard has only two expansion slots, one of which is already occupied by a Wi-Fi adapter. The remaining slot is usually used for a GPS module.

The ASUS U3S resembles the U1F externally except that it provides two extra inches of the display diagonal. This should make it a more comfortable work tool because the U1F’s 11.1” display seems too small for many users. The 13.3” LCD matrix of the U3S is an optimal compromise between comfort and dimensions.

Now we are going to check out the notebook’s design and accessories and benchmark its two graphics cores in our tests.

Package and Accessories

The notebook is packed into a blue-and-white box with a Stylish Mobility slogan. The notebook’s ability to change its performance level in order to increase the battery life is not mentioned, though.

The ASUS Green label on the side of the internal box reports that the notebook complies with the RoHS directive, being manufactured without such hazardous substances as lead, mercury, cadmium, hexavalent chromium or polybrominated flame retardants.

There is a rich selection of accessories inside the box. Besides the notebook proper, it contains a 6-cell 4800mAh battery, a power adapter with LED indicator, a modem cable (RJ-45), a TV cable, documentation (“Quick Installation Guide”, 2-year warranty certificate, a list of authorized service centers worldwide, user manual, etc), a black Bluetooth mouse, a napkin for cleaning the LCD panel, a HDMI → DVI adapter, a bag and a pouch to carry the notebook around, a cable brace, an external 120GB HDD in a leather pouch and two cables (USB and eSATA), an external GPS antenna (the notebook comes with a GPS module), and a set of discs. The discs are:




The mouse is colored black and glossy to match the notebook itself. Its bottom and the separator between the buttons look like shiny metal to comply with the overall design style. The mouse is shipped in a fabric pouch together with a user manual and two AA batteries. To change the batteries, you should pull the top panel back, away from the buttons.


The LG GSA-T20N DVD-burner is external to reduce the notebook’s dimensions and weight. It has a standard black case as we’ve seen with other ASUS products (for details see our article called Asus U1F: Ultra Compact High-End Notebook) and is connected to the computer with a special cable that combines a USB and a power connector.


The LG GSA-T20N has the following speed characteristics:



Exterior Design and Ergonomics

The U3S resembles ASUS’ U1F model but is larger. The lid is made from a robust magnesium-aluminum alloy and covered with piano lacquer. The lid surface can serve as a mirror if you keep it clean – the black glossy surface gets soiled and dusted just too easily.

Well, you can prefer the white version of the U3S that doesn’t look dirty after you touch it.

The internal color scheme is the same as on the outside: the leather trimming around the touchpad is white in the white-colored version of the notebook.

There is no lid lock here. The elements that keep the notebook closed or fix the lid at the desired angle are located in the screen hinges. There is a jutting metallic piece at the front of the lid to help you open the notebook up.

The display hinges are hidden in the tube that stretches the entire width of the notebook.

The notebook can be unfolded by a large enough angle, yet not by a full 180 degrees.

The hinge tube accommodates all the notebook’s indicators together with various buttons and ports. Two instant-launch buttons (Power4Gear eXtreme and Splendid) are placed near the left display hinge together with a microphone port.

The Power4 Gear+ eXtreme utility offers several power modes that vary in such parameters as CPU frequency, screen brightness, Windows power management scheme, etc. Five Power4 Gear+ modes are available when the notebook is connected to the wall socket and seven when it works on its battery.

The Power button is near the right hinge together with status indicators:

Num Lock and Scroll Lock indicators are missing.

The Power button and the instant-launch keys are not convenient as they are deep in the hinge tube. It’s hard to hit them with your finger. The surface of the buttons is rough, however, to prevent your finger from slipping off.

The indicators are based on LEDs of three colors: white in the bottom row and blue in the top row. The battery indicator is orange as usual.

When the lid is closed, the bottom row of indicators is invisible, but that’s not a problem because the most important indicators (battery and power) are visible irrespective of the position of the lid.

The external color scheme is continued inside. There are rubber pads along the black screen bezel for a softer contact between the notebook’s bottom and the lid. A 1.3-megapixel web-camera is integrated into the top of the bezel. The camera’s angle of view is regulated only by adjusting the tilt of the display.

The silvery keyboard and the narrow steel bezel around the touchpad are the single elements that stand out among the black of the notebook’s body. The surface below the keyboard is trimmed with black leather, which feels nice to your hands. The notebook’s body is made from carbon fiber, a very robust material, to protect the hardware components inside it.

The ASUS U3S is equipped with a widescreen 13.3” LCD matrix that has a native resolution of 1280x800 pixels. The viewing angles seem large subjectively. The display features a LED-based backlight that provides lush and saturated colors. The difference from classic LCD matrixes with fluorescent backlights is visible to the eye. The matrix has a glassy coating that produces flares and reflections of brightly lit objects behind the user’s back. You have to take care about proper ambient lighting when you sit down to work with this notebook.

The glassy display is manufactured using a special polymer coating (ASUS Color Shine technology) that is meant to improve image quality and color saturation.

Besides it, there are two more technologies, ASUS Crystal Shine and ASUS Splendid Video Enhancement.

Crystal Shine is claimed to provide a higher brightness of the screen so that the notebook could produce a sharp picture with vivid colors even under bright ambient lighting, which makes it suitable for watching movies and playing games.

The notebook also features ASUS Splendid Video Enhancement technology. It allows adjusting the onscreen image by means of preset modes. These modes are selectable with the Fn+C combination; the current mode can be see in the onscreen menu.

The U3S offers 16 grades of screen brightness as every other notebook from ASUS, but it is virtually impossible to see anything in the screen at the lowest grades: the image gets too dark. The brightness level is adjusted by pressing Fn together with F5 and F6.

We measured the brightness and contrast of the notebook’s display using a Pantone ColorVision Spyder with OptiCAL 3.7.8 software. We selected the highest brightness setting before this test. ASUS’ power-saving technologies are not enabled automatically in the DC mode, and the values are roughly similar. The brightness is indeed high enough for using the notebook under bright daylight, but the contrast ratio is rather low.

AC power source:

DC power source:

Your overall impression about a notebook is the total of numerous trifles, of course. Particularly, the keyboard of the U3S contributes a lot to this total. It is a real masterpiece of engineering art. It offers 86 silvery keys, soft yet springy, framed into a narrow bezel. The keys do not rattle. The only drawback we could find here is that the Arrow buttons are placed level with the keyboard’s baseline, which makes them likely to be pressed accidentally.

The bottom left corner of the keyboard is occupied by a Control button – that’s convenient for people who are used to Control-involving shortcuts. A numpad (combined with the main keyboard) and two Windows keys are available: the Context Menu key is placed over one key to the right of the spacebar; the Windows Logo key is to the left of the spacebar. The functional keys are smaller than others. Home, Page Up, Page Down and End are placed in a column on the right. Pause, Print Screen, Insert and Delete continue the row of functional keys.

The touchpad resembles the one of the U1F model, but wider like the notebook overall. It is highly sensitive and has a vertical scrolling zone on the right. In between the touchpad buttons there is a fingerprint scanner that works together with the Trusted Platform Module to ensure the confidentiality of your data. There is no scrolling joystick – there is just no place for it left here.

If you are using an external mouse and want to avoid the touchpad reacting to an accidental touch, you may want to block the latter by pressing Fn+F9.

The removal of the optical drive out of the notebook’s body freed the side panels for various I/O interfaces – and the manufacturer made good use of this opportunity.

The notebook’s left panel carries the following components (from left to right):

Besides the WLAN switch, you can enable the notebook’s Wi-Fi and Bluetooth interfaces by pressing Fn together with F2.

The right panel offers the following:

If you change the position of the performance switch when the notebook is turned on, you’ll be asked to reboot the machine in the following manner:


The notebook’s back panel provides the following components (from left to right):

The bottom panel has only two compartments: HDD and memory. Besides a memory slot occupied by a 1GB module, the latter compartment offers access to almost all the internals of the notebook, though. The optional 3G module is in the HDD compartment, and you have to unscrew the appropriate cover to access the SIM card. A Reset/Shutdown button is placed here as well. Stickers with the model info and the OS serial number are glued to the memory compartment cover. The bottom panel is all drilled for ventilation – you can place the notebook on your laps without any danger of overheat.


The stereo speakers are built into the notebook’s body close to the user. The speakers face downward, yet have a loud sound. The sound volume is adjusted by pressing Fn together with F10, F11, and F12.

The notebook comes with a 4800mAh 6-cell battery. 3-cell and 9-cell batteries, with capacities of 2400 and 7200mAh, respectively, are available, too. The former matches the notebook’s outline perfectly while the larger battery sticks out of the case. Each three battery cells add an extra 200 grams to the notebook’s weight.

The manual and spring-loaded locks are located on the battery’s body to prevent it from slipping out of the notebook.




The ASUS U3S is based on an Intel Core 2 Duo T7500 processor with a clock rate of 2.2GHz (65nm Merom core with 4 megabytes of shared L2 cache). The FSB frequency is 800MHz.

The Core 2 Duo T7500 supports Intel’s 64-bit extensions to the x86 architecture and also features Intel Wide Dynamic Execution technology which means more decoders and execution units in the CPU core.


Besides Intel’s traditional Enhanced SpeedStep technology that gives the notebook’s software and BIOS the control over the CPU frequency multiplier (to reduce it under low loads), this CPU supports Dynamic Power Coordination (the power consumption of the cores can be independently adjusted depending on the current load; one core may even slip into Deep Sleep mode with the lowest power consumption possible), Dynamic Cache Sizing (unused segments of the CPU cache can be turned off to save power), and FSB Frequency Switching (the FSB clock rate is automatically lowered at low loads). We couldn’t spot the effect from the latter technology with the appropriate tools, yet the test results are indicative of its benefits. For more information about Intel’s Core 2 Duo processors refer to our review called "Santa Rosa + Vista: Three Notebooks Reviewed" or to the manufacturer’s website.

This implementation of the Santa Rosa platform also incorporates an Intel PRO/Wireless 4965AGN adapter and an Intel Crestline GM965 chipset. The 965 series chipsets support a FSB frequency of 800MHz. The GM965 offers a PCI Express x16 interface for an external graphics card and also features an integrated graphics core called Intel Graphics Media Accelerator X3100. Connected to the North Bridge via a special-purpose Direct Media Interface, the South Bridge (ICH8-M) supports three Serial ATA-300 ports, ten USB 2.0 ports and Intel High Definition Audio. It also offers six PCI Express x1 lanes to connect external devices. For more information about the platform, visit the manufacturer’s website.

GMA X3100 is the first graphics core from Intel to support shaders on the GPU. As a result, the new integrated chipset features improved performance and compatibility with 3D applications, particularly with Windows Vista’s Aero interface. The X3100 can also support DirectX 10 using the recently released driver. The new core is clocked at a frequency of 500MHz and incorporates 8 unified shader processors for 3D rendering as well as for video playback acceleration. Thanks to them, the X3100 provides hardware acceleration and post-processing for video content in MPEG-2 and WMV9 formats. The core doesn’t support the new compression standards H.264 and VC-1 (Blu-ray and HD-DVD), though. Besides higher performance, the new graphics core has acquired more advanced power-saving features, mostly meant to reduce the consumption of the LCD panel which is the main power consumer in a notebook together with the CPU. The X3100 supports Display Power Saving Technology 3.0 that is automatically adjusts the brightness and contrast of the screen to reduce power consumption yet keep the image quality high. The Display Refresh Rate Switching technology can be used to reduce the refresh rate of the screen when the notebook works on its battery.

The Crestline GM965 chipset provides the PCI Express x16 interface ASUS engineers connected a discrete graphics core GeForce Go 8400M G to. It is accompanied with 128 megabytes of dedicated graphics memory and can also be allotted a portion of system memory for a total of 896MHz. The GPU is manufactured on 0.08-micron tech process that ensures a lower power draw in comparison with 0.11- and 0.09-micron chips. That’s why the junior model in the 8xxx series is specially intended for thin and light notebooks. It supports DirectX 10 Shader Model 4.0, PureVideo technology for high-quality HD video playback and PowerMizer technology for efficient power management. You can refer to the manufacturer’s website for details about the GeForce Go 8400M G. The basic specs of the GeForce Go 8400 series are listed in the table below:

The notebook comes with a Hitachi HTS541616J9SA00 hard disk drive (2.5” form-factor, 5400rpm spindle rotation speed, 160GB capacity, SATA interface).

The ASUS U3S works with DDR2-667 SDRAM, the fastest memory available on the Santa Rosa platform. The single accessible slot is occupied by a 1GB module. A 512MB module is installed on the mainboard. The memory works in dual-channel mode because some of it is used by the GPU. The maximum amount of memory the notebook supports is 2560MB.

We measured the temperature of the hottest spots on the notebook’s surfaces with an infrared thermometer after it had worked for half an hour in PCMark 2005 (the ambient temperature remained constant at 23°C during this test) and got the following numbers:

So, the notebook is rather cool even under load. The following table lists the specs of the ASUS U3S:

Test Methods

We have changed our list of benchmarks due to the growing popularity of Microsoft Windows Vista and the poor compatibility of the new mobile platform Santa Rosa with Windows XP. Some benchmarking applications are the same as before, though.

So, the notebook’s hard drive was formatted in NTFS before the tests. Then we installed Microsoft Windows Vista Ultimate and drivers from the included disc.

The following settings were used for the tests:

Two power modes were used. First, we selected the High Performance power mode for maximum performance and the shortest battery life. Then we switched to the Power Saver mode for the maximum battery run-down time.

Our tests:

  1. Performance benchmarks: synthetic (SiSoftware Sandra 2007, PCMark 2004 1.3.0, PCMark 2005 1.2.0, PCMark Vintage, SYSMark 2007), real-life applications (DivX 6.7, iTunes 7.3, Photoshop CS2, Microsoft Excel 2007, WinRAR 3.7, Microsoft Movie Maker 6.0, CINEBENCH 10), and games (3DMark 2001SE Pro, 3DMark 2003 3.6.0, 3DMark 2005 1.2.0, 3DMark 2006 1.1.0, Half-Life 2, F.E.A.R., Quake 4)
  2. Battery life tests (MobileMark 2007)

We replaced our traditional Battery Eater Pro with MobileMark 2007 because the former is not compatible with Windows Vista.

There are three test modes in Mobile Mark 2007:


Synthetic Benchmarks

As usual, we will first run our synthetic benchmarks.

The SiSoftware 2007 suite features an updated enhanced-functionality interface, runs on three platforms (Win32 x86, Win64 x64, WinCE ARM), contains 13 tests and 34 informational modules, and supports a large range of devices thanks to the developer’s collaboration with Intel, AMD, ATI, SiS and VIA. The program is supported in six languages and has a free Lite version for personal and educational purposes. SiSoftware Sandra measures the overall performance of the system as well as that of each of its subsystems.

PCMark benchmarks the computer performance in office and office-related applications and also produces performance scores for the main subsystems (CPU, memory, graphical, and disk subsystem). PCMark 2005 carries on the tradition of complex benchmarks of the series and uses fragments of real-life applications as tests. This makes it somewhat more relevant for end-users as opposed to fully synthetic benchmarks. After running a series of 11 tests on the different components of the system, the program calculates an overall performance score in units called PCMarks. PCMark 2005 can check a computer out at processing HD video and encoding audio, and offers enhanced tests of the CPU and hard disk under multi-threaded load. The overall score is calculated by the formula: PCMark Score = 87 x (the geometric mean of the basic tests), where the geometric mean is calculated as (Result 1 x Result 2 x…) divided by the number of results. PCMark Vantage is the first synthetic benchmarking suite developed for Vista. It contains more tests than the previous versions of the benchmark.

The notebook performs just as you could expect it to. The CPU performance is lowered in the battery mode due to the activation of the power-saving features implemented in the Merom core. Oddly enough, tools that report the CPU and FSB frequencies do not spot the reduction which is visible in the test results. As for the graphics subsystem, the discrete GeForce 8400M G core is obviously better than the integrated GMA X3100. The notebook doesn’t have enough of system memory to pass the appropriate test of PCMark Vantage when using the integrated graphics core because the latter is allotted some of the system memory for its purposes. The twofold reduction of the memory test results in the battery mode is obviously due to the FSB Frequency Switching technology. 

The new version of SYSMark is intended to reveal a system’s performance under different types of load. It simulates a user who is solving practical tasks in a few popular applications. The benchmark issues a few ratings that are indicative of the system performance under different loads. The results for each test load are shown separately:

The notebook has a good result due to its CPU, which bears the highest load in SYSmark 2007.

The E-Learning test emulates the creation of an educational website with diverse media content. This script makes use of the following applications: Adobe Illustrator CS2, Adobe Photoshop CS2, Macromedia Flash 8 and Microsoft PowerPoint 2003.

That’s not a high score, but we haven’t seen other notebooks in this test yet. The notebook’s power-saving technologies are enabled in the battery mode, affecting its performance.

The next script is about creating video clips using special effects. The clips are combined out of several sources, including static images. The result is prepared in two formats: HD and for online viewing. The following software is utilized here: Adobe After Effects 7, Adobe Illustrator CS2, Adobe Photoshop CS2, Microsoft Windows Media Encoder 9, and Sony Vegas 7.

The results seem to be good as far as we can compare them with the statistics we’ve already got.

The Productivity test models typical office activities such as sending e-mail, processing data, managing a project, working with documents. Applications employed: Microsoft Excel 2003, Microsoft Outlook 2003, Microsoft PowerPoint 2003, Microsoft Word 2003, Microsoft Project 2003, and WinZip 10.0.

The top-end representative of the Core 2 Duo series copes with office applications easily.

The final script from SYSMark 2007 is about creating an architectural presentation including a photorealistic image of the building and a clip with a flyby of it. Two applications are used: AutoDesk 3ds Max 8 and SketchUp 5.

This is almost a test of the CPU alone. Its result is proportional to the CPU performance.

Real Applications

Next we tested the notebooks in a few real-life applications.

The Core 2 Duo T7500 finds it easy to encode video with the DivX 6.7 codec.

MP3 encoding is an easy task for the notebook’s high-frequency CPU as well.

This test script from Adobe Photoshop emulates the processing of five 5-megapixel photographs. The notebook delivers high performance here, too. Note that its performance differs noticeably between the two cores.

The U3S shows its best again thanks to the high CPU frequency. The threefold performance hit in the battery mode is due to the aggressive power-saving measures.

Data compression is not a problem for a top-performance CPU that could use a large amount of system memory.

In the next test a script is used that prepares a video clip for uploading to YouTube. The clip was made out of four video fragments captured from a digital camera. The Core 2 Duo T7500 copes with the job easily. The notebook’s performance is much lower in the battery mode, though.

The results of the final rendering test are proportional to the CPU frequency.

Graphics Benchmarks

Next we tested the notebook in four versions of 3DMark: 3DMark 2001SE Pro, 3DMark 2003 3.6.0, 3DMark 2005 1.2.0 and 3DMark 2006 1.1.0.

3DMark uses its own rendering engine to create a set of 3D scenes that load the graphics subsystem in various ways. Compared with the previous version, 3DMark 2005 uses Shader Model 2.0x/3.0 instead of Shader Model 1.x, provides full compatibility with Shader Model 2.0, includes more complex tests (over a million polygons per each frame), and employs normal maps. 3DMark 2006 brings support for HDR, Uniform Shadow Maps, and multi-core CPUs. It is overall oriented at Shader Model 3.0, but two out of its four graphics tests work within the Shader Model 2.0 framework.


GMA X3100, the most advanced of Intel’s integrated graphics cores, is beaten in every test by the weakest GPU of Nvidia’s GeForce 8 series. Let’s see what the U3S can do in real games, though.

Gaming Benchmarks

So, the U3S is quite capable of running modern 3D games at an acceptable speed.

Battery Life

Battery life is just as important a parameter of a notebook as its performance. The notebook’s battery life was measured with MobileMark 2007. We disabled standby and hibernate mode for the test.

The first scenario, Productivity, emulates the user’s working in typical office applications. The load is not constant as the user is frequently distracting from his work. The second scenario measures the notebook’s battery life when the user is reading text from the screen in Adobe Reader. The third scenario is about DVD playback in InterVideo WinDVD.

So, the notebook can last for 50 minutes longer on its battery if you use the integrated graphics core X3100. The design concept is thus justified. We did expect somewhat better results from the U3S in this test, yet 2.5 hours under load is quite a long time, too.


The U3S is an expensive product and it is not free from certain design drawbacks, yet it is a product you just want to have. With its original design and exclusive materials, it is like a rare diamond. Moreover, it delivers good performance and features broad functionality. From a technical standpoint, the U3S is a well-balanced solution in terms of weight, size, and power consumption. It is not a cheap buy, yet it won’t disappoint you if you choose it.