Asus ZenBook UX51 Developer Review

Asus ZenBook UX51 Developer Review

Here are comparison pictures of my new ZenBook and my old Dell Precision.



A couple months ago I was in the market for a new laptop. I have been a developer on Microsoft platforms for my entire career, so Ideally I wanted a Windows based laptop. I have friends that own MacBook Pro Retina laptops that use Parallels to develop in Visual Studio. I thought there just had to be a Windows based laptop that was an equal to the MackBook.

The things that were most important for me were in order of importance: performance, mobility, connectivity, and display resolution / size. I did not want a touch screen. Read my Windows 8 article for more on that topic.


I have not run performance profiling tools. If you want to see that kind of detailed results, check the review on NotebookCheck noted in the further reading section below. I provided links to review specs of all the laptops mentioned in this article. What follows is the performance based on my experience.


Generally I just close the lid on my ZenBook which triggers sleep mode. Even if I press the power button it is just configured to go into sleep mode. The only time I fully shutdown or restart is after a weekly windows update. This restart does not occur every week, since not all updates require a restart.

When I open the lid after a sleep mode it starts up in what seems to me almost instantaneous; or about 1 second via a stopwatch. That time is to the user selection / login screen. If I type my password as fast as I can and hit enter, then I appear where I left off in what seems instantaneous to me. I opened the lid, typed my password, and then continued typing this blog entry without waiting for the computer to do anything.

For the rare occasion in which I fully shutdown I do it via the settings menu (Windows Key + I), then ‘Power’. You can also access it with an extra step from the charms menu (Windows Key + C), then ‘settings’ then ‘Power’; for those that remember that shortcut easier. A full boot after a shutdown takes my zenbook about 9 1/2 seconds (by manual stopwatch) to the login screen. Then there is no perceivable lag after logging in until I can open an application.

I generally do not full reboot since I then have to reopen all my applications to where I left off working. Also the battery on standby only uses 0.4 Watts compared to 9.5 to 12.7 Watts when on and idling, so battery use during standby shouldn’t be an issue.

Here is my Development oriented Start Screen.


Visual Studio 2012

Visual Studio is where I spend most of my time during development. Open times vary greatly based on if the laptop is running on battery or not. This is an intentional feature of the processor to preserve battery life. This can be turned off, but it really only affect start time in Visual Studio, not normal work within the solution. So I feel it is worth letting the computer throttle the processor when on battery.

I open Visual Studio with the start screen disabled; So on startup I stopped timing the startup when the cursor changed from a wait cursor into a normal cursor. I did not stop it just when the splash screen disappeared.

When plugged in, opening Visual Studio takes about 6 seconds. Then opening the candor-core solution (on github) takes about 9 more seconds. When running on battery, just opening Visual Studio takes about 15 seconds. Then opening the candor-core solution takes about 21 seconds to fully load.

Given how Visual Studio loads projects in the background, I could have opened a file to edit before it was fully loaded. I just waited to stop my stopwatch until after the progress bar embedded in solution explorer showed it was 100% loaded.


I personally don’t mind the sluggish load time when on battery if it means I can work a couple extra hours. I also usually just leave Visual Studio running unless I know I am not writing code over the next few hours of using the computer. So that reduces the amount of time that this delay in loading affects me.

The candor-core solution consists of 9 projects, and a few solution items. It consists of a database project, 5 normal class libraries, a unit test class library, a windows service project, and an MVC4 web application. After doing a ‘Clean solution’, windows explorer shows the folder has 649 files, 313 of which are in the solution. The rest of the files are in the build process for packaging up NuGet libraries, or just in the solution’s ‘packages’ folder. Your mileage may vary with different sized solutions, however I picked this one because I felt it was average and it was the largest solution on my ZenBook.

Music Player

My second most used application is playing music while I develop. Windows 8 comes with a good media player. It is not a desktop app, so it can only be loaded from the start screen and not from the desktop. My library on my laptop is only 967 songs at 2.79GB. The music player loads instantly. The album covers are not instantly visible, but they load in over a period of 1-2 seconds after the app opens.

SQL Server Management Studio (SSMS)

I don’t use SSMS very often, since many of the tasks I can complete inside Visual Studio. However, opening SSMS only takes about 1-2 seconds. Connecting to localhost\SQLExpress takes about a second. It is fast, when I need to use it.

I typically just use SSMS to create a database, and add a couple users; Typically I add an owner user with schema edit rights and a limited app user. Then I do the rest via a database project in Visual Studio.

Other Apps

I use Notepad++, Github for Windows, Fiddler 4, and many other general utilities as well. None of them have any perceivable delays in opening them, and they are all just as easy to use on this Windows 8 laptop as on any Windows 7 computer; So I won’t delve into the details of those applications on Windows 8.

Windows Experience Index (WEI)

If you look at the WEI you may be disappointed with the overall score of 5.8. This is due to the Desktop graphics performance, which I don’t quite ‘get’. I can do the ‘shake’ gesture of a window to get the rest of the windows to close and everything seems fluid to me. I’m not sure what else would stress the desktop graphics.

The next lowest score is 6.7 for the Gaming graphics performance. This isn’t bad given the NVIDIA GeForce GT 650M 2048MB video card. I don’t plan on using this laptop for 3D gaming very much, but it’s good to know it can handle games at moderate resolutions well; as confirmed by the review at NoteBookCheck.

The processor and memory have a great score at 7.6 and 7.7 respectively.

The best portion of the score is the hard disk at 8.3. This is due to the dual SSD drives. I’m not sure how you can get much better at this point in time, at least in a laptop.

The WEI score is with the laptop plugged in, since WEI won’t calculate a score while on battery. So when on battery when processor throttling in in play, actual performance may be lower. But you can turn that off if it noticibly affects you.


Room for Expansion Improvement

I am slightly disappointed that ASUS soldered a 4GB RAM chip to the motherboard instead of an 8GB chip. It would be nice if they offered an option with an 8GB chip soldered on, and left the second upgradeable RAM slot empty for a later upgrade.  With that said I have not upgraded my RAM past the initial 8GB (4GB x 2) of RAM.  I can swap out one of the 4GB chips for an 8GB chip in the future.

Mobility / Build Quality

Battery life and weight are the two most important aspects of mobility, and the ZenBook doesn’t disappoint. It has much higher than average battery life, especially when you are doing low impact things like typing code. The Apple MacBook Pro Retina is one of the few laptops with better battery life, but not by much. Under normal conditions the ZenBook’s 70 Wh Lithium-Polymer, 4750 mAh, 8 cell battery gets 5 hours and 17 minutes; while the MacBook Pro Retina gets about 6 hours. The nearest competition Dell XPS 15 gets 4hr 39min, the Sony VAIO S15 gets 4hr 34min. There are others with better battery life, but they sacrifice other features.

The weight of the ZenBook has been reported as 2.1Kg and 2.2Kg. I suppose it depends on which options you choose, but both answers make for a super lightweight laptop. This is one area where the MacBook Pro Retina squeaks in a win at 2.0Kg tied with the Sony VAIO also at 2.0Kg. The Dell XPS 15 is much further behind at 2.7Kg. With the close weight of these laptops (except the Dell), weight didn’t end up being a determining factor between these laptops.

The power brick on the ZenBook is better than most. When sitting next to a MacBook Pro power brick it looks about the same size and shape. The ZenBook power brick is approx 0.2Kg. The Dell XPS 15 power brick is 0.3Kg. I didn’t see the weight of the Sony VAIO power brick listed.

It is worth noting that the original release of this laptop had a fan noise issue, which gave it a lower score on NoteBookCheck. It was since fixed before I purchased mine. I barely hear the fan in normal scenarios. I don’t have the proper measuring equipment to list the Decibel level post BIOS update.


The ZenBook has better connectivity than the average ultrabook, including the MacBook Pro. The ZenBook has 3 USB 3.0 ports, one of which is a ‘Sleep n charge’ which charges a connected device even when the Zenbook is powered off; It is indicated on the left side next to the port with a lightning bolt icon. One of the USB ports is on the right, perfect for a mouse in the rare occasion that you want to use one. The other two are on the left side for additional devices, or for you left handed mouse users. The further back port on the left is the sleep n charge port, so it doesn’t get in the way of a left handed mouse connection.

The ZenBook also has 2 video connector options, HDMI and Mini-VGA. A Mini-VGA to standard VGA connector dongle is included with with the ZenBook. The HDMI is on the left further toward the back from the USB connectors. The Mini-VGA connector is on the right also toward the back from the USB connector.

The ZenBook also comes with a sub-woofer connector, and it ships with a small subwoofer accessory to plug into that port. The sound on this subwoofer is a great enhancement for the sound when I am working at my primary desk. It is a great compliment to the above par ‘Bang and Olufsen’ 2.2 sound system built into the ZenBook. I don’t carry the sub-woofer when I work away from home, since I would primarily use headphones when working remotely anyway.

The right side also has a card reader that supports SD, MMC, and SHDC memory cards. I don’t have much use for these as a developer. But when I take my ZenBook on vacation, it is nice to be able to download pictures from my camera and have them sync to Skydrive overnight, assuming I can get on the internet where I am vacationing.

The left side has a compact ethernet connector. When nothing is plugged in the connector collapses down allowing the case a tapered profile. The ZenBook also has an advanced N (A,B,G,N) Intel wireless connection.

Display / Resolution

The display is a 15.6″ monitor with a maximum resolution of 1920×1080. The display is IPS technology that is bright and non-glare, which helps it avoid annoying reflections and makes it easier to read when around sunlight. The Apple and Dell competitors have glare type screens, giving the Asus ZenBook an advantage for outdoor or near window use.

The Apple Retina display is certainly superior in resolution due to the 2880×1800 pixels, but I was unable to differentiate an Apple Retina display from an Asus display at normal distance viewing. It is rare to find a website that has images of a resolution in which you could tell the difference.  I was also unable to see an improvement with the Retina display in website fonts in the browser while zoomed in.

Pre-installed applications

ASUS pre-installed a total of 18 applications that appear on the ‘all apps’ view of the start screen. Some of them are supposedly performance improvers, but I am not sure if they are attributing to my excellent performance or not.


The applications that are running at startup and their start time (in milliseconds) include:

  • ACMON: 104 ms
  • ASUS Quick Gesture Exe (x2): 58 ms + 53 ms
  • ASUS Smart Gesture Loader (x3 app processes): 244ms
  • ASUS WebStorage Panel: 296ms

Total ASUS tool startup time: 755ms. This time may not even be sequential, since there are 4 processor cores or 8 logical processors, due to hyper-threading, on this laptop.


Other pre-installed applications I currently have running now that I did not manually start and their RAM usage include:

  • ACMON (32 bit): 1.6MB
  • ASUS InstantOn Program (32 bit) x2: 1.1MB + 3.6MB
  • GFNEXSrv (32 bit): 0.5MB
  • Power4Gear Hybrid: 0.9MB
  • ASUS Smart Gesture Center: 2.0MB
  • ASUS Smart Gesture Helper: 0.7MB
  • ASUS Smart Gesture Loader: 1.3MB
  • ACEngSrv Module (32 bit): 2.1MB
  • ADLDR Service (32 bit): 0.8MB
  • ASUS USB Charger Plus (32 bit): 0.7MB
  • ATK Media (32 bit): 0.9MB
  • ATKOSD2 (32 bit): 1.2MB
  • HControl (32 bit): 1.1MB
  • KBFiltr (32 bit): 0.9MB
  • ASUS Live Update (32 bit): 2.6MB
  • ASUS Quick Gesture Exe: 1.4MB
  • ASUS Quick Gesture Exe (32 bit): 1.3MB

Total ASUS Memory footprint: 28.3MB.

This is practically nothing, since Music takes 151.8MB, Windows Explorer 64.7MB, SyDrive 54.2MB, and Dropbox 49.1MB. Total RAM usage at this point is 33%

After loading Visual Studio 2012 with the candor-core open source project loaded it takes another 301.7MB. I currently have all my typical applications open and I am only using 41% of my 8GB of physical memory.



I have only had 1 Blue Screen of Death (BSOD) so far on this ASUS, over a month ago. I believe it was related to a device driver. A windows update since then must have fixed the issue.

The experience of the BSOD wasn’t too unpleasant. I save frequently, so I didn’t lose anything. The computer collects a memory dump and restarts rather quickly. On reboot it asked if I would allow sending the memory dump to Microsoft. It also included a link to let me open the dump before sending it, for the people that know how to read it.


The ASUS ZenBook UX51V is the best laptop I have ever owned. Actually it is the best computer I have ever owned. If you are a Windows ecosystem developer, or really anything but a native iOS developer, I recommend this laptop over anything else if you can afford it.

Since you cannot compile iOS apps on anything but Apple hardware, this cannot be used for native iOS development; This is due to licensing restrictions, not technical limitations.

Further Reading

Windows 8: Start Screen versus Desktop

Windows 8 start screen, Desktop, and Touch

Rick Broida: Does it make sense to buy a PC with a touch screen?

Rockford Lhotka: Is Windows 8 a success?

Other Reviews

NoteBookCheck: ASUS Zenbook UX51

B&H Photo and Video: product listing as reviewed here, $2,265 in April 2013

NoteBookCheck Comparison Product: Apple MacBook Pro Retina 15

NoteBookCheck Comparison Product: Dell XPS 15 (L521X)

NoteBookCheck Comparison Product: Sony Vaio SV-S1511X9E/B

Scott Hanselman: Review: The Lenovo X1 Carbon Touch is my new laptop
(A recent review of a competitor of the ZenBook, with a touch screen)

About the Author

Michael Lang

Co-Founder and CTO of Watchdog Creative, business development, technology vision, and more since 2013, Developer, and Mentor since 1999. See the about page for more details.


  • Avatar By flopjoke

    This is a good review, based on actual usage. My main question is this: isn’t this laptop as expensive as a Macbook Pro? If it is possible to buy a laptop with the same configuration and replace the HDD with SSDs, we’d theoretically get the same performance for much cheaper. I’m just wondering what made you pay the premium price and if it really is worth it.

    • mlang74 By mlang74

      The zenbook laptop does have dual 256GB SSD drives (512GB total). This is the same specs as the macbook pro retina. See the specs as in the referenced reviews.

      Any comparison in this review to macbook is to the macbook pro retina released in summer 2012 as linked to at the bottom of the review. Compared to a normal macbook, I would consider the zenbook to be much better (lighter, more performant, and more).

      The macbook pro retina is much more expensive than the asus zenbook ux51 per my shopping experience. Including the addition of parallels to run visual studio the prices I saw had the macbook pro retina at about $500 more expensive.